Fix i915 warnings on skl_dram_get_channel_info()

[Kai-Heng Feng]

[Impact]
Kernel warning from i915's skl_dram_get_channel_info().

[Fix]
Update how i915 gets DRAM information.

[Test]
No more kernel splat after the fix gets applied.
Anything graphics related seems to work fine.

[Where problems could occur]
The change only applies to gen11 and gen12 gfx so the scope is limited.
If the PCODE doesn't work as intended, this might cause regression.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-oem-5.10/5.10.0-1050.52 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-oem-5.10 - 5.10.0-1050.52

---------------
linux-oem-5.10 (5.10.0-1050.52) focal; urgency=medium

  * focal/linux-oem-5.10: 5.10.0-1050.52 -proposed tracker (LP: #1944904)

  * Fix A yellow screen pops up in an instant (< 1 second) and then disappears
    before loading the system (LP: #1945932)
    - SAUCE: drm/i915: Stop force enabling pipe bottom color gammma/csc

  * CVE-2021-3759
    - memcg: enable accounting of ipc resources

  * Fix i915 warnings on skl_dram_get_channel_info() (LP: #1943923)
    - drm/i915: Nuke not needed members of dram_info
    - drm/i915/gen11+: Only load DRAM information from pcode
    - drm/i915: Rename is_16gb_dimm to wm_lv_0_adjust_needed

  * Focal update: 5.10.68 upstream stable release (LP: #1944975)
    - drm/bridge: lt9611: Fix handling of 4k panels
    - btrfs: fix upper limit for max_inline for page size 64K
    - xen: reset legacy rtc flag for PV domU
    - bnx2x: Fix enabling network interfaces without VFs
    - arm64/sve: Use correct size when reinitialising SVE state
    - PM: base: power: don't try to use non-existing RTC for storing data
    - PCI: Add AMD GPU multi-function power dependencies
    - drm/amd/amdgpu: Increase HWIP_MAX_INSTANCE to 10
    - drm/etnaviv: return context from etnaviv_iommu_context_get
    - drm/etnaviv: put submit prev MMU context when it exists
    - drm/etnaviv: stop abusing mmu_context as FE running marker
    - drm/etnaviv: keep MMU context across runtime suspend/resume
    - drm/etnaviv: exec and MMU state is lost when resetting the GPU
    - drm/etnaviv: fix MMU context leak on GPU reset
    - drm/etnaviv: reference MMU context when setting up hardware state
    - drm/etnaviv: add missing MMU context put when reaping MMU mapping
    - s390/sclp: fix Secure-IPL facility detection
    - x86/pat: Pass valid address to sanitize_phys()
    - x86/mm: Fix kern_addr_valid() to cope with existing but not present entries
    - tipc: fix an use-after-free issue in tipc_recvmsg
    - ethtool: Fix rxnfc copy to user buffer overflow
    - net/{mlx5|nfp|bnxt}: Remove unnecessary RTNL lock assert
    - net-caif: avoid user-triggerable WARN_ON(1)
    - ptp: dp83640: don't define PAGE0
    - net/l2tp: Fix reference count leak in l2tp_udp_recv_core
    - r6040: Restore MDIO clock frequency after MAC reset
    - tipc: increase timeout in tipc_sk_enqueue()
    - drm/rockchip: cdn-dp-core: Make cdn_dp_core_resume __maybe_unused
    - perf machine: Initialize srcline string member in add_location struct
    - net/mlx5: FWTrace, cancel work on alloc pd error flow
    - net/mlx5: Fix potential sleeping in atomic context
    - nvme-tcp: fix io_work priority inversion
    - events: Reuse value read using READ_ONCE instead of re-reading it
    - net: ipa: initialize all filter table slots
    - gen_compile_commands: fix missing 'sys' package
    - vhost_net: fix OoB on sendmsg() failure.
    - net/af_unix: fix a data-race in unix_dgram_poll
    - net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup
    - x86/uaccess: Fix 32-bit __get_user_asm_u64() when CC_HAS_ASM_GOTO_OUTPUT=y
    - tcp: fix tp->undo_retrans accounting in tcp_sack...