usb: dwc3: Initialize val,val1 with 0 as they can be used uninitialized

If in the function dwc3_msm_power_collapse_por, dwc3 is not on
DWC_usb31 core and dwc3_msm doesn't have dual port then val1
can be used uninitialized. To prevent such scenario initialize
val1 and val with zero.

Change-Id: I359c596d3dace6c00475eb22fb64a37631f240b1
Signed-off-by: Rohith Kollalsi <rkollals@codeaurora.org>