drm/amd/display: disable CRTCs with NULL FB on their primary plane (V2)

drm/amd/display: disable CRTCs with NULL FB on their primary plane (V2)

The below commit

"drm/atomic: Try to preserve the crtc enabled state in drm_atomic_remove_fb, v2"

introduces a slight behavioral change to rmfb. Instead of disabling a crtc
when the primary plane is disabled, it now preserves it.

This change leads to BUG hit while performing atomic commit on amd driver.

As a fix this patch ensures that we disable the CRTC's with NULL FB by returning
-EINVAL and hence triggering fall back to the old behavior and turning off the
crtc in atomic_remove_fb().

V2: Added error check for plane_state and removed sanity check for crtc.

Signed-off-by: Shirish S <shirish.s@amd.com>
Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>