msm: board-9615: Create a separate board file for gpiomux

Move the MSM9615 gpiomux configuration to a dedicated board
file.

Change-Id: I26c2d5cceab60d3429a7313939a5f7aaecfc7e32
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
4 files changed