USB: dwc3-msm: Enable async irq wakeup capability only if required

If driver is depending on PMIC for VBUS and ID events, then async
interrupt is not required to set wakeup capable during cable
disconnect or when dcp is connected. Otherwise this interrupt can be
fired before PMIC notification during system suspend and could mess up
run time pm counters. Hence enable async irq wakeup capability
during bus suspend and disable it during device resume.

CRs-Fixed: 634833
Change-Id: Ifea0150ee947823ba4f8183af911e150fde61f1f
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>