drm/tc358762: Set the pre_enable_upstream_first flag to configure DSI host

TC358762 wants the DSI host to be prepared before it is powered up, so
set the flag to request that the upstream bridges have their
pre_enable called first.

Link: https://github.com/raspberrypi/linux/commit/f57b6e4732ddbedc785c8d1d52c4f1c7101dbfa1



Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Rahul T R <r-ravikumar@ti.com>