drm/bridge: ite-it6263: Support HDMI vendor specific infoframe

IT6263 supports HDMI vendor specific infoframe.  The infoframe header
and payload are configurable via NULL packet registers.  The infoframe
is enabled and disabled via PKT_NULL_CTRL register.  Add the HDMI vendor
specific infoframe support.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250908-it6263-vendor-specific-infoframe-v2-1-3f2ebd9135ad@nxp.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>