board: Add support for Sielaff i.MX6 Solo board

The Sielaff i.MX6 Solo board is a control and HMI board for vending
machines. Add support for this board.

The devicetree files are taken from pending changes in the Linux
kernel that are available from linux-next and will likely be
part of Linux v6.9.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
diff --git a/board/sielaff/imx6dl-sielaff/MAINTAINERS b/board/sielaff/imx6dl-sielaff/MAINTAINERS
new file mode 100644
index 0000000..c0d3a09
--- /dev/null
+++ b/board/sielaff/imx6dl-sielaff/MAINTAINERS
@@ -0,0 +1,9 @@
+Sielaff i.MX6 Solo Board
+M:	Frieder Schrempf <frieder.schrempf@kontron.de>
+S:	Maintained
+F:	arch/arm/dts/imx6dl-sielaff*
+F:	board/sielaff/imx6dl-sielaff/
+F:	configs/imx6dl_sielaff_defconfig
+F:	doc/board/sielaff/imx6dl-sielaff.rst
+F:	include/configs/imx6dl-sielaff.h
+F:	include/configs/kontron-sl-mx6ul.h