exynos5250: usb: Fix VBus gpio numbers for ehci and xhci controllers

The gpio_*() apis require the exact gpio line number to deduce
the gpio bank and the gpio pin addresses.
So fix the gpio number for VBUS used for EHCI ports as well as
XHCI ports on exynos5250 boards.

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>