drivers: video: tegra: vi: implement probe/remove

drivers: video: tegra: vi: implement probe/remove

add probe/remove callback functions for tegra_vi to keep and release
regulator properly.

bug 200003367

Change-Id: I790d7d1822cacd1d8b01913ecedf6d73d83a8786
Signed-off-by: Charlie Huang <chahuang@nvidia.com>
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/416306
Reviewed-on: http://git-master/r/552474
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Eric Chuang <echuang@nvidia.com>
Reviewed-by: Robert Shih <rshih@nvidia.com>
Tested-by: Robert Shih <rshih@nvidia.com>