sony-laptop: support new hotkeys on the P, Z and EC series

Add new mappings for assist, VAIO, zoom and eject buttons present on
refurbished P, Z and EC models.

Reported-by: Gyorgy Jeney <nog.lkml@gmail.com>
Reported-by: Stephan Mueller <smueller@chronox.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/include/linux/sonypi.h b/include/linux/sonypi.h
index 4f95c1a..0e6dc38 100644
--- a/include/linux/sonypi.h
+++ b/include/linux/sonypi.h
@@ -112,6 +112,7 @@
 #define SONYPI_EVENT_VOLUME_DEC_PRESSED		70
 #define SONYPI_EVENT_BRIGHTNESS_PRESSED		71
 #define SONYPI_EVENT_MEDIA_PRESSED		72
+#define SONYPI_EVENT_VENDOR_PRESSED		73
 
 /* get/set brightness */
 #define SONYPI_IOCGBRT		_IOR('v', 0, __u8)