input: sensor: Add device tree parser for mma8x5x

Add device tree parser to allow Freescale accelerometer driver can
get interrupt and position configuration from device tree.

Change-Id: I1467a72977414264715b30dd5c26f2aaf5a1f7ae
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>