board: freescale: Add entry for imx8mm_evk_fspi_defconfig

Add entry for imx8mm_evk_fspi_defconfig in
board/freescale/imx8mm_evk/MAINTAINERS

Signed-off-by: Mamta Shukla <mamta.shukla@leica-geosystems.com>
Signed-off-by: Thomas Haemmerle <thomas.haemmerle@leica-geosystems.com>
Tested-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
diff --git a/board/freescale/imx8mm_evk/MAINTAINERS b/board/freescale/imx8mm_evk/MAINTAINERS
index b031bb0..875adf58 100644
--- a/board/freescale/imx8mm_evk/MAINTAINERS
+++ b/board/freescale/imx8mm_evk/MAINTAINERS
@@ -4,3 +4,4 @@
 F:	board/freescale/imx8mm_evk/
 F:	include/configs/imx8mm_evk.h
 F:	configs/imx8mm_evk_defconfig
+F:  configs/imx8mm_evk_fspi_defconfig