usb: Use IPA of data fifo with DBM

DBM register is need to program with data fifo address, as DBM is
interface to access data fifo by USB controller. Hence use IPA
address from USB function driver. IPA and physical address are same
for no smmu case with USB.

Change-Id: I93f7735e9aa4533b93853f496ec63213720ea90a
Signed-off-by: Mayank Rana <mrana@codeaurora.org>