Revert "misc: apq8084_dock: Fix GPIO contention with audio"

The audio driver no longer uses the dock detection GPIO, so there
is no more contention. Revert commit 024ba0ad as the dock driver
should now call gpio_request() once again.

Change-Id: I5de21aca4b923529ff5758a955025844dd239b61
Signed-off-by: Jack Pham <jackp@codeaurora.org>