Input: introduce EV_MSC Timestamp

Some devices provides the actual timestamp (hid_dg_scan_time in win8 ones)
computed by the hardware itself. This value is global to the frame and is
not specific to the multitouch protocol.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h
index 5588285..935119c 100644
--- a/include/uapi/linux/input.h
+++ b/include/uapi/linux/input.h
@@ -851,6 +851,7 @@
 #define MSC_GESTURE		0x02
 #define MSC_RAW			0x03
 #define MSC_SCAN		0x04
+#define MSC_TIMESTAMP		0x05
 #define MSC_MAX			0x07
 #define MSC_CNT			(MSC_MAX+1)