imx: add imx8x based deneb board

Add support for Capricorn Deneb SoM variant.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/board/siemens/capricorn/MAINTAINERS b/board/siemens/capricorn/MAINTAINERS
index 5d81aaf..bc7d163 100644
--- a/board/siemens/capricorn/MAINTAINERS
+++ b/board/siemens/capricorn/MAINTAINERS
@@ -3,7 +3,9 @@
 S:	Maintained
 F:	board/siemens/capricorn/
 F:	include/configs/capricorn-common.h
+F:	include/configs/deneb.h
 F:	include/configs/giedi.h
 F:	include/configs/siemens-ccp-common.h
 F:	include/configs/siemens-env-common.h
+F:	configs/deneb_defconfig
 F:	configs/giedi_defconfig