[XS] Change in libgfxinit[main]: gma tgl: Pcode CDCLK_PREPARE_FOR_CHANGE is not mandatory

[Jérémy Compostella (Code Review)]

Attention is currently required from: Angel Pons, Anil Kumar K, Anil Kumar K, Jeremy Compostella, Jérémy Compostella, Nick Vaccaro, Nico Huber, Tarun Tuli.

Jérémy Compostella has uploaded a new patch set (#43) to the change originally created by Tarun Tuli. ( https://review.coreboot.org/c/libgfxinit/+/69341?usp=email )

Change subject: gma tgl: Pcode CDCLK_PREPARE_FOR_CHANGE is not mandatory
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gma tgl: Pcode CDCLK_PREPARE_FOR_CHANGE is not mandatory

Pcode mailbox `CDCLK_PREPARE_FOR_CHANGE' command is not available till
BIOS Reset CPL and may fail when called too early.

This command is actually not mandatory to set the CDCLK sucessfully on
this platform.  This patch keeps the `CDCLK_PREPARE_FOR_CHANGE' command
but ignores return errors if any.

Change-Id: I0514e404a7b580d1e35af7b39c1bd77183f11058
Signed-off-by: Jeremy Compostella 
Signed-off-by: Anil Kumar 
---
M common/tigerlake/hw-gfx-gma-power_and_clocks.adb
1 file changed, 5 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/libgfxinit refs/changes/41/69341/43