ARM: dts: msm: Remove Camera GPIO configuration for 8996 ADP

cam_snapshot & cam_focus button support is not available
for msm8996 agave ADP. Hence remove the GPIO configurations
associated with it.

Change-Id: I6692e39d7c5a8c27907acc405774d6e65926ee78
Signed-off-by: Bharathraj Nagaraju <snbraj@codeaurora.org>