MAINTAINERS: Add Mihail to Komeda DRM driver

I'll be the main point of contact.

Cc: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Sean Paul <sean@poorly.run>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021150123.19570-1-mihail.atanassov@arm.com