drm/amd/display: ensure PSR force_static flag can always be set

[HOW&WHY]
Make sure psr_force_static() can always be called regardless of
psr_allow_active value.

Reviewed-by: Harry Vanzylldejong <harry.vanzylldejong@amd.com>
Reviewed-by: Evgenii Krasnikov <Evgenii.Krasnikov@amd.com>
Reviewed-by: Nicholas Choi <Nicholas.Choi@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Evgenii Krasnikov <Evgenii.Krasnikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>