MAINTAINERS: grab build system responsibility

Since nobody else stepped up, I hereby claim responsibility for the
build system.

Change-Id: I580b906d15fc2f049f0072e7b4608b1f19db83ab
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/10277
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index b054f4d..bd49c41 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -139,6 +139,14 @@
 S:	Supported
 F:	util/lint/
 
+BUILD SYSTEM
+M:	Patrick Georgi <patrick@georgi-clan.de>
+S:	Supported
+F:	Makefile
+F:	*.inc
+F:	util/kconfig
+F:	util/sconfig
+
 THE REST
 M:	Stefan Reinauer <stefan.reinauer@coreboot.org>
 L:	coreboot@coreboot.org