usb: phy: Add and use missed OTG FSM inputs/outputs

Several input/output variables missed in current FSM implementation.
This patch adds and makes use of them as specified in OTG and EH
supplement to USB2.0.

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>