MAINTAINERS: add Luca Ceresoli as reviewer for DRM bridge code

MAINTAINERS: add Luca Ceresoli as reviewer for DRM bridge code

I am actively working on drm_bridge.c and recently also
drm_bridge_connector.c, especially for the DRM bridge hotplug work. Being
in Cc would ensure I won't miss related patches and can review them
promptly.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260430-maintainers-add-r-drm_bridge-v1-1-3e2523faf349@bootlin.com