MAINTAINERS: Add entries for touchbar display driver

Add the MAINTAINERS entries for the driver

Acked-by: Sven Peter <sven@svenpeter.dev>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250224-adpdrm-v8-5-cccf96710f0f@gmail.com


Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>