usb: dwc3-msm: Enable hs_phy_irq after driver_data is populated

There was an issue where the hs_phy_irq was triggered very early
during device boot-up, even before the driver_data was populated.
Since the hs_phy_irq is not enabled at this point, it causes a NULL
pointer exception.
So to fix this, enable hs_phy_irq after driver_data is being populated.

CRs-fixed: 719911
Change-Id: I2c31b0e9af41979821d38b9bafc08af098c373db
Signed-off-by: Azhar Shaikh <azhars@codeaurora.org>