drm: xlnx: zynqmp_dpsub: Set input live format

Program live video input format according to selected media bus format.

In the bridge mode of operation, DPSUB is connected to FPGA CRTC which
almost certainly supports a single media bus format as its output. Expect
this to be delivered via the new bridge atomic state. Program DPSUB
registers accordingly.

Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240416-dp-live-fmt-v4-6-c7f379b7168e@amd.com