usb: phy-msm-usb: Set dma bit mask to 32

ChipIdea USB controller supports only 32 bit addressing. Some targets
support 64 bit or 32 bit addressing. In order to support ChipIdea
controller on 64 bit targets dma bit mask must be defined as 32.

Change-Id: Ia183cc6a03c45d533fc7d672db55fe24748d9307
Signed-off-by: Azhar Shaikh <azhars@codeaurora.org>