ARM: dts: cros-ec-keyboard: Add alternate keymap for KEY_LEFTMETA

On newer keyboards this key is in a different place. Add both options to
the keymap so that both new and old keyboards work.

Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

arch/arm/boot/dts/cros-ec-keyboard.dtsi

@@ -46,6 +46,7 @@ MATRIX_KEY(0x02, 0x08, KEY_LEFTBRACE)
 			MATRIX_KEY(0x02, 0x09, KEY_F8)
 			MATRIX_KEY(0x02, 0x0a, KEY_YEN)
 
+			MATRIX_KEY(0x03, 0x00, KEY_LEFTMETA)
 			MATRIX_KEY(0x03, 0x01, KEY_GRAVE)
 			MATRIX_KEY(0x03, 0x02, KEY_F2)
 			MATRIX_KEY(0x03, 0x03, KEY_5)