MAINTAINERS: Update drm.git URL

Now that the main DRM tree has moved to Gitlab, adjust the MAINTAINERS
git trees to reflect the location change.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20240226152123.131406-1-mripard@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Author: mripard

MAINTAINERS

@@ -614,7 +614,7 @@ AGPGART DRIVER
 M:	David Airlie <airlied@redhat.com>
 L:	dri-devel@lists.freedesktop.org
 S:	Maintained
-T:	git git://anongit.freedesktop.org/drm/drm
+T:	git https://gitlab.freedesktop.org/drm/kernel.git
 F:	drivers/char/agp/
 F:	include/linux/agp*
 F:	include/uapi/linux/agp*
@@ -6996,7 +6996,7 @@ L:	dri-devel@lists.freedesktop.org
 S:	Maintained
 B:	https://gitlab.freedesktop.org/drm
 C:	irc://irc.oftc.net/dri-devel
-T:	git git://anongit.freedesktop.org/drm/drm
+T:	git https://gitlab.freedesktop.org/drm/kernel.git
 F:	Documentation/devicetree/bindings/display/
 F:	Documentation/devicetree/bindings/gpu/
 F:	Documentation/gpu/