exynos5: lcd: Free gpio in machine specific set_power callback

exynos5: lcd: Free gpio in machine specific set_power callback

The platform_lcd driver suspend/resume functions call the machine
specific set_power function. This function requests a gpio without
freeing it resulting in the following error message during suspend/
resume:
"gpio_request: gpio-180 (GPX3) status -16"
Free the requested gpio to fix the above error.

BUG=chrome-os-partner:8921
TEST=Test S2R on Daisy and ensure that the gpio request error goes away.

Change-Id: If124e94a6ae4a72a14d9ff95927074c4f84dd3d6
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Reviewed-on: https://gerrit-int.chromium.org/20784
Commit-Ready: Olof Johansson <olofj@google.com>
Reviewed-by: Olof Johansson <olofj@google.com>