ALSA: add headphone over current switches

Some CODECs monitor current drawn by headphone power amplifer.
If current consumed goes over pre-defined threshold, CODEC would
communicate to host processor. Then, CODEC driver would propagate
the event so user-space application can react accordingly.
Add support to propagate over current events for both
left headphone and right headphone through ALSA jack framework.

Change-Id: Ieef36f070a4478a5a80ec4c8b0cc81464abd75ad
Signed-off-by: Patrick Lai <plai@codeaurora.org>
diff --git a/include/linux/input.h b/include/linux/input.h
index d9133f2..b1f7161 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -812,6 +812,8 @@
 #define SW_KEYPAD_SLIDE		0x0a  /* set = keypad slide out */
 #define SW_FRONT_PROXIMITY	0x0b  /* set = front proximity sensor active */
 #define SW_ROTATE_LOCK		0x0c  /* set = rotate locked/disabled */
+#define SW_HPHL_OVERCURRENT	0x0d  /* set = over current on left hph */
+#define SW_HPHR_OVERCURRENT	0x0e  /* set = over current on right hph */
 #define SW_MAX			0x0f
 #define SW_CNT			(SW_MAX+1)