MAINTAINERS: Update info for TI display drivers

Add drm-misc as the git tree for tilcdc and omapdrm. Change Tomi's email
to point to ideasonboard.com instead of kernel.org.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230619082323.20575-1-tomi.valkeinen@ideasonboard.com