regulator: tps65132: support for active discharge on input pin

regulator: tps65132: support for active discharge on input pin

Some configurations use delay mechanisms on the
tps65132 enable pin, to keep the regulator enabled
for some time after the enable signal goes low.
Add support to actively discharge this delay
mechanism.

Bug 1630935
Bug 200118211

Change-Id: If7a8fd39d862f35924d7799740f01ead0f65bb71
Signed-off-by: Daniel Solomon <daniels@nvidia.com>
Reviewed-on: http://git-master/r/763398
(cherry picked from commit cadc2c292de1fa677b3b52cf2ea72bd58661ddd1)
Reviewed-on: http://git-master/r/771172
Reviewed-by: Jon Mayo <jmayo@nvidia.com>