asus-wmi: Add ambient light sensor toggle key

Ausu laptops issue key 0x7A when the toggle ALS key is pressed (Fn+A on
Asus U38N). Update the key_entry so userspace can handle the event.

Tested on Asus U38N.
Signed-off-by: Nick Leiten <nickleiten@gmail.com>
Reviewed-By: Corentin Chary <corentin.chary@gmail.com>
[dvhart: cleaned up commit message and comment line length]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

drivers/platform/x86/asus-nb-wmi.c

@@ -356,6 +356,7 @@ static const struct key_entry asus_nb_wmi_keymap[] = {
 	{ KE_KEY, 0x67, { KEY_SWITCHVIDEOMODE } }, /* SDSP LCD + CRT + TV */
 	{ KE_KEY, 0x6B, { KEY_TOUCHPAD_TOGGLE } },
 	{ KE_IGNORE, 0x6E, },  /* Low Battery notification */
+	{ KE_KEY, 0x7a, { KEY_ALS_TOGGLE } }, /* Ambient Light Sensor Toggle */
 	{ KE_KEY, 0x7D, { KEY_BLUETOOTH } }, /* Bluetooth Enable */
 	{ KE_KEY, 0x7E, { KEY_BLUETOOTH } }, /* Bluetooth Disable */
 	{ KE_KEY, 0x82, { KEY_CAMERA } },