misc: apq8084_dock: Fix GPIO contention with audio

The docking station detect GPIO is also used by the audio
driver, however only one entity should call gpio_request,
as all subsequent calls will fail. Requesting it here will
cause audio driver to fail to probe. Fix it by not calling
gpio_request().

Change-Id: Iadb9786fcf772d433c4b30026f8afa0bf76e35c3
Signed-off-by: Jack Pham <jackp@codeaurora.org>