dt-bindings: input: mediatek,mt6779-keypad: update maintainer

Fengping has no longer interest and time to maintain this driver so he
agreed to transfer maintainership over to me.
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220421140255.2781505-1-mkorpershoek@baylibre.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml

@@ -7,7 +7,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Mediatek's Keypad Controller device tree bindings
 
 maintainers:
-  - Fengping Yu <fengping.yu@mediatek.com>
+  - Mattijs Korpershoek <mkorpershoek@baylibre.com>
 
 allOf:
   - $ref: "/schemas/input/matrix-keymap.yaml#"