[media] OMAP_VOUT: Fix build break caused by update_mode removal in DSS2

The DSS2 driver does not support the configuration of the update_mode of a
panel anymore. Remove the setting of update_mode done in omap_vout_probe().
Ignore configuration of TE since omap_vout driver doesn't support manual update
displays anyway.

Signed-off-by: Archit Taneja <archit@ti.com>
Tested-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>