usb: musb: OMAP3xxx: Fix device detection in otg & host mode

usb: musb: OMAP3xxx: Fix device detection in otg & host mode

In OMAP3xxx with OTG mode or host only mode, When the device
is inserted after the gadget driver loading the enumeration was not
through. This is because the mentor controller will start sensing the
ID PIN only after setting the session bit.
So after ID-GND, need to set the session bit for mentor to get it
configured as A device.

This is a fix to set the session bit again in ID_GND notification handler.
Tested with OMAP3630Zoom3 platform.

Signed-off-by: Hema HK <hemahk@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>