Split the USB MMR init steps out into a helper func that both the platform
init and the resume code may call.
Then while suspending, the gpio_vrsel will change from high to low which
will generate a wakeup event and resume the system immediately, so we need
to manually drive it low before we sleep.
Signed-off-by: Bob Liu <lliubbo@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Felipe Balbi <balbi@ti.com>