mmc: tegra: configure voltage regulators

mmc: tegra: configure voltage regulators

-Added support for voltage regutators, padctrl setting,
prod setting are done using new frame work.
-Added required voltage singal switch, pre_voltage_switch
functions.

Bug 200204385
Bug 200193768

Change-Id: Ieb6e3a993594245d29eee8c9585e4ab3af4d1779
Signed-off-by: Anubhav Jain <anubhavj@nvidia.com>
Signed-off-by: R Raj Kumar <rrajk@nvidia.com>
Signed-off-by: Naveen Kumar Arepalli <naveenk@nvidia.com>
Reviewed-on: http://git-master/r/1164066
Reviewed-by: Venu Byravarasu <vbyravarasu@nvidia.com>