ARM: tegra: whistler: add wakeup source for KBC

Adding KBC as a wakeup source for Whistler board.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/boot/dts/tegra20-whistler.dts

@@ -539,6 +539,7 @@ kbc {
 		nvidia,repeat-delay-ms = <160>;
 		nvidia,kbc-row-pins = <0 1 2>;
 		nvidia,kbc-col-pins = <16 17>;
+		nvidia,wakeup-source;
 		linux,keymap = <0x00000074	/* KEY_POWER */
 				0x01000066	/* KEY_HOME */
 				0x0101009E	/* KEY_BACK */