drm/i915/display: add support for DMC wakelocks

In order to reduce the DC5->DC2 restore time, wakelocks have been
introduced in DMC so the driver can tell it when registers and other
memory areas are going to be accessed and keep their respective blocks
awake.

Implement this in the driver by adding the concept of DMC wakelocks.
When the driver needs to access memory which lies inside pre-defined
ranges, it will tell DMC to set the wakelock, access the memory, then
wait for a while and clear the wakelock.

The wakelock state is protected in the driver with spinlocks to
prevent concurrency issues.

BSpec: 71583
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412094148.808179-2-luciano.coelho@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>