BF2: Add support for eMMC HW reset

[Liming Sun]

SRU Justification:

[Impact]
This is a cherry-pick fix from upstream to Add support for BF2 eMMC HW reset

[Fix]
BLueField eMMC RST_N register is implemented as secure, thus the default hw_reset() implementation won't work. This patch provides BlueField specific hw_reset() which send SMC call to ATF to update the same RST_N register.

[Test Case]
Same functionality and testing as on BlueField-1/2.

[Regression Potential]
Same behavior from user perspective.

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

This bug is awaiting verification that the linux-bluefield/5.15.0-1048.50 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-jammy-linux-bluefield' to 'verification-done-jammy-linux-bluefield'. If the problem still exists, change the tag 'verification-needed-jammy-linux-bluefield' to 'verification-failed-jammy-linux-bluefield'.

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!