ARM: dts: exynos: fix USB 3.0 pins supply being turned off on Odroid XU

ARM: dts: exynos: fix USB 3.0 pins supply being turned off on Odroid XU

On Odroid XU LDO12 and LDO15 supplies the power to USB 3.0 blocks but
the GPK GPIO pins are supplied by LDO7 (VDDQ_LCD).  LDO7 also supplies
GPJ GPIO pins.

The Exynos pinctrl driver does not take any supplies, so to have entire
GPIO block always available, make the regulator always on.

Fixes: 88644b4c750b ("ARM: dts: exynos: Configure PWM, usb3503, PMIC and thermal on Odroid XU board")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201015182044.480562-3-krzk@kernel.org
Tested-by: Gabriel Ribba Esteva <gabriel.ribbae@gmail.com>