tegra124: Active dc/sor register change immediately

When doing DP attach, we need to make sure the register change to
take effect immediately, otherwise it may fail to catch the attach
timing.

BRANCH=None
BUG=chrome-os-partner:28128
TEST=Display works and system boots up on Nyan and Big

Original-Change-Id: I569dc435a1aa4aac0d5ecd0655d2ad87a791246d
Original-Signed-off-by: Vince Hsu <vinceh@nvidia.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/200414
Original-Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Original-Reviewed-by: Jimmy Zhang <jimmzhang@nvidia.com>
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 47b86e2893fa667bebada6a0e0b443886dd5ee02)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Icf809b46e675bbdb8633d9a4f31d005d6644bd2a
Reviewed-on: http://review.coreboot.org/7951
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
1 file changed