usb: dwc3-msm: Expose functions for dbm ep reset in lpm

USB suspend/resume sequence requires a DBM EP
reset. This commit add the support for resetting
the DBM EP which is linked to a given USB EP. In addition,
it adds the necessary functionality to query the DBM as to
whether the DBM EP reset is necessary.

Change-Id: I18449b3584ff82a638d9cd413cb7d8e825b92f99
Signed-off-by: Dov Levenglick <dovl@codeaurora.org>
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>