MAINTAINERS: Add entry for Samsung S6D7AA0 LCD panel controller driver

Add myself as maintainer of the Samsung S6D7AA0 panel driver.

Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230519170354.29610-4-aweber.kernel@gmail.com