OMAP3: PM: add T2 interrupt line mux setting, and enable on 3430SDP

This patch changes for setting the padconf value for sys_nirq line
which is connected to T2 INTR1.  This will fix the T2 keypad wakeup
issue on OMAP3 SDP.

Signed-off-by: Teerth Reddy <teerth@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>