Frequency of intel-ipu6-dkms not set due to IVSC CSI changes

[tewaro]

I upgraded from 6.14 to 6.17 hwe kernel and found my camera unable to run.

I came across this issue in journalctl:

```
intel-ipu6-isys intel-ipu6-isys0: can't get link frequency (-2)
```

I then manually applied the fix here: https://github.com/intel/ipu6-drivers/pull/425

This allowed the camera to work again.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
ProcVersionSignature: Ubuntu 6.17.0-1011.11-oem 6.17.9
Uname: Linux 6.17.0-1011-oem x86_64
ApportVersion: 2.28.1-0ubuntu3.8
Architecture: amd64
CasperMD5CheckMismatches: ./boot/grub/i386-pc/eltorito.img ./boot.catalog
CasperMD5CheckResult: fail
CurrentDesktop: sway
Date: Tue Feb 24 02:42:53 2026
InstallationDate: Installed on 2024-08-26 (547 days ago)
InstallationMedia: Ubuntu 22.04.3 LTS "Jammy Jellyfish" - Release amd64 (20230807.2)
SourcePackage: ipu6-drivers
UpgradeStatus: Upgraded to noble on 2025-06-24 (245 days ago)

[tewaro (tewaro)]

[Impact]
intel-ipu6-dkms fails to build against kernels >= 6.12 (no_llseek removal, asm/unaligned, macro changes, follow_pte)
and camera streaming fails on kernels >= 6.15 (IVSC link frequency API change).
This affects all Ubuntu 24.04 users with Intel IPU6 cameras on HWE or OEM kernels.
[Test Plan]
1. Install the updated package on Ubuntu 24.04 with kernel 6.17
2. Verify: dkms status | grep ipu6 shows "installed"
3. Verify: v4l2-ctl -d /dev/video0 --stream-mmap --stream-count=5 streams frames
4. Verify: Camera works in Firefox/Cheese
[Where problems could occur]
Regression on older kernels (6.8) - mitigated by version guards
[Other Info]
PPA with fix: ppa:tewaro/ipu6-drivers
Tested on Dell Precision 5680 with OV02C10 sensor, kernel 6.17.0-1011-oem, kernel 6.8.0-101-generic

[tewaro (tewaro)]

Here is the first patch from my ppa solving compiler issues.

[tewaro (tewaro)]

Second patch for frequency fix.