power: qpnp-smbcharger: add otg-usb-id notifications

The USB ID pin is not routed to the MSM on MSM8994. It only goes to the
PMI8994 charger. The USB driver will need to rely on the charger driver
to do OTG detection.

Add the interrupt for USBID changes in the smbcharger driver, and
whenever the USB RID is grounded, notify the USB driver through the USB
power supply that USB OTG is connected.

Change-Id: I8826fc1ab2472b4b21b787eda764e0a694d7bbda
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>