usb: phy: fsm: update OTG HNP state transition

According to:"On-The-Go and Embedded Host Supplement to the USB Revision 2.0
Specification July 27, 2012 Revision 2.0 version 1.1a"

- add a_wait_vrise to a_wait_vfall
- update condition from a_wait_vrise to a_wait_bcon

Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>