MAINTAINERS: add myself

Add myself to MAINTAINERS file.

Change-Id: I959ef193b69095b05ae9e42bd10d3b21001e0bc8
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/14262
Tested-by: build bot (Jenkins)
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
1 file changed