cgtqmx6eval: Fix defconfig name

After the conversion to SPL the defconfig was renamed, so adjust it.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
diff --git a/board/congatec/cgtqmx6eval/MAINTAINERS b/board/congatec/cgtqmx6eval/MAINTAINERS
index c41ebf5..48c0889 100644
--- a/board/congatec/cgtqmx6eval/MAINTAINERS
+++ b/board/congatec/cgtqmx6eval/MAINTAINERS
@@ -3,4 +3,4 @@
 S:	Maintained
 F:	board/congatec/cgtqmx6eval/
 F:	include/configs/cgtqmx6eval.h
-F:	configs/cgtqmx6qeval_defconfig
+F:	configs/cgtqmx6eval_defconfig