arm: odroid: enable/disable usb host phy for exynos4412

Enable/disable the usb host phy on the odroid U/X2 boards which are based
on the Exynos4412 SOC.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>