video: tegra: host: enable actmon watermark intr

video: tegra: host: enable actmon watermark intr

Add support to use watermark interrupts:

- Adds nvhost interrupt callback to actmon interrupts,
  if actmon_irq is set for device.
- Adds callbacks to set high and low watermark values.
- Removes unused counter code.

Bug 1515087

Change-Id: Ibff29a534c4580225a7a7b2e18af18dfe150565b
Signed-off-by: Shridhar Rasal <srasal@nvidia.com>
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/497377
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit