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.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>