usb: phy-msm: Add support for external USB ID detection

On some platforms, pmic hardware can detect USB ID state and
notify USB driver about USB ID status through usb power supply's
POWER_SUPPLY_PROP_USB_OTG property. Hence add support for
handling such platforms in USB driver.

CRs-Fixed: 1086015
Change-Id: Ia310f5dc77b33fd594a94a8c130c0e00a7e31216
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>