drm/amd/display: Prevent PSR disable/reenable in HPD IRQ

[Why]
When HPD IRQ occurs, it triggers a PSR disable and reenable
directly through dc layer.
Since it does not pass through the power layer, the layer
that tracks whether PSR is enabled or disabled and which
masks are set, this layer is now out of sync with the real
PSR state in FW.
Theoretically PSR can be enabled during hw programming
sequences or any other situation where we must disable PSR.

[How]
Check if PSR is enabled before doing PSR disable/reenable.

Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>