video: tegra: host: Disable irq when clock gating

Disable host1x interrupts when clock gating host1x. This fixes a race
where host1x interrupt was raised at the same time when host1x clock
is turned off.

Bug 1031724

Change-Id: I169cd5796608b8888a6b48ed99bb5da754559b2c
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/125129
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>