Added runtime programming for the differences in EHCI interface between
OMAP3EVM revisions (Rev >= E) and (Rev < E).
Changes:
- EHCI PHY reset GPIO pin is 21 on Rev >= E while Rev < E
uses GPIO pin 135.
- Rev >= E uses EHCI Vbus enable GPIO22 line.
- Rev >= E uses GPIO61 to select EHCI port either on main board or
on Mistral Daughter Card (MDC). OMAP3EVM Rev < E doesn't have
EHCI port on main board.
- Currently GPIO61 it programmed to enable EHCI port on main
board only.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>