riscv: Add Microchip MPFS Icicle board support

This patch adds Microchip MPFS Icicle board support.
For now, NS16550 serial driver is only enabled.
The Microchip MPFS Icicle defconfig by default builds
U-Boot for M-Mode with SMP support.

Signed-off-by: Padmarao Begari <padmarao.begari@microchip.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
diff --git a/board/microchip/mpfs_icicle/MAINTAINERS b/board/microchip/mpfs_icicle/MAINTAINERS
new file mode 100644
index 0000000..22f3b97
--- /dev/null
+++ b/board/microchip/mpfs_icicle/MAINTAINERS
@@ -0,0 +1,7 @@
+Microchip MPFS icicle
+M:	Padmarao Begari <padmarao.begari@microchip.com>
+M:	Cyril Jean <cyril.jean@microchip.com>
+S:	Maintained
+F:	board/microchip/mpfs_icicle/
+F:	include/configs/microchip_mpfs_icicle.h
+F:	configs/microchip_mpfs_icicle_defconfig