drm: xlnx: mixer: Fix switching to 4K after 1080p

drm: xlnx: mixer: Fix switching to 4K after 1080p

This patch fixes the issue of switching to higher resolution like 4K
once the primary layer has been set to a lower resolution like 1080p.
This is done by disabling the need to check frame parameters like width,
height if the plane to be set is the primary plane.

Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
Reviewed-by: Saurabh Sengar <saurabhs@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>