drivers: tegra: max77665-flash: flash level update

drivers: tegra: max77665-flash: flash level update

add logic to assign flash/torch level 0 as disable flash/torch functions.
from the hardware's spec, level 0 means the lowest current 16.625mA.

add torch-by-i2c trigger option and set it as default.

also optimized the power on/off sequences.

bug 1155623
bug 1110380
bug 1116953

Change-Id: I1d592a173c4694287dff1543b21a92e3efcd8f2e
Signed-off-by: Charlie Huang <chahuang@nvidia.com>
(cherry picked from commit e799bf696300020045ab7284e007a87accbf9404)
Reviewed on: http://git-master/r/#change,145113
Reviewed-on: http://git-master/r/146034
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Thomas Cherry <tcherry@nvidia.com>
Rebase-Id: R58ae8f7497e2f18d6174e6e8cbd75ebb32b6b337