video: display_timing: make parameter const
video: display_timing: make parameter const

As the device_node pointer is not changed in of_get_display_timing and
parse_timing_property it can be a const pointer.

Signed-off-by: Steffen Trumtrar <acd73cdea7391c1e626e2d4b16b2f41438ca5396@pengutronix.de>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs