input: qpnp-keypad: change API to kernel 3.10 compatible

Keypad driver is using kernel 3.4 API to build keymap. Making this
change to be compatible with 3.10 kernel.

Change-Id: I7aaa39e1a09c594a53f9c03fde162051c14becad
Signed-off-by: Chun Zhang <chunz@codeaurora.org>