USB: phy-msm-usb: Fix 3p3 and 1p8 regulators ON/OFF sequence

For various external chargers detection support require to turn
on 3p3 PHY regulator. For this, PMIC driver calls USB call back
to turn on/off regulator based on need basis. Currently USB
driver is turning on/off the 3p3 regulator only, this may lead
while 3p3 regulator is ON, 1p8 regulator may be off. This may
cause damage to 1p8 transistors. In order to avoid damage to 1p8
transistors, require 1p8 rail to be turned on whenever the
3p3 rail is on. Similarly part of turning off regulator, require
to first turn-off 3p3 and then turn-off 1p8.

CRs-Fixed: 1086015
Change-Id: I11c88317d16f8c664361207680fc79218d6223d4
Signed-off-by: Sujeet Kumar <ksujeet@codeaurora.org>