drm/amd/display: Remove DPMS state dependency for fast boot

[Why]
The DPMS state of a display should not impact whether we want to enable fast boot.
Currently fast boot is not enabled when resuming from S4 because of this.

[How]
Remove check for DPMS state when determining if fast boot
can be applied.

Signed-off-by: SivapiriyanKumarasamy <sivapiriyan.kumarasamy@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>