regulator: core: add support for active discharge enable/disable property

regulator: core: add support for active discharge enable/disable property

Add regulator DT property to add support for configuring the rail's
active discharge enable/disable forcefully. If properties are absent
then it will be POR default.

Change-Id: Ia3a99c6e9aec37ef2824e169e1ae99884163bc25
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/824694
(cherry picked from commit eff460b9d82bd634da66625d05451fae5385d80c)
Signed-off-by: Venkat Reddy Talla <vreddytalla@nvidia.com>
Reviewed-on: http://git-master/r/825309
GVS: Gerrit_Virtual_Submit