msm: fsm9900: Add initial board files for fsm9900

Add an initial board file and the initial gpiomux
configuration file for the FSM9900 target

Change-Id: I84d3badd42e5ac2124afeafd3a6b8635456d0a21
Acked-by: Kaushik Sikdar <ksikdar@qti.qualcomm.com>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>