drm/amd/display: DPP low mem pwr related adjustment -Part I

drm/amd/display: DPP low mem pwr related adjustment -Part I

[why]
Default low pwr mem state get chagned.
SW needs to wake mem up first
also need to put back to LS again after use: will do in Part II.

Reviewed-by: Leo Chen <leo.chen@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>