drm/amdgpu: remove ATPX_DGPU_REQ_POWER_FOR_DISPLAYS check when hotplug-in

In amdgpu_atif_handler, when hotplug event received, remove
ATPX_DGPU_REQ_POWER_FOR_DISPLAYS check. This bit's check will cause missing
system resume.

Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org