drm/amd/display: WA for DF keeps awake after S0i3.

drm/amd/display: WA for DF keeps awake after S0i3.

[Why]
DF keeps awake after S0i3 resume due to DRAM_STATE_CNTL
is set by bios command table during dcn init_hw.

[How]
As a work around, check STATE_CNTL status before init_hw,
if it is 0 before init_hw and set to 1 after init_hw,
change it to 0.

Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>