disp: msm: sde: fix hdr meta data property handling

Allow clients to reset the hdr meta data property even when
connector does not support hdr. This is required for shell stop
case cleanup when dp connector might be in disconnected state.

Change-Id: Ie0db61530216f1fab6c952933425259d32cfc834
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>