arm64: Add Xilinx ZynqMP support

Add basic Xilinx ZynqMP arm64 support.
Serial and SD is supported.
It supports emulation platfrom ep108 and QEMU.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index eef70d0..1b5b155 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -173,6 +173,12 @@
 F:	arch/arm/cpu/armv7/zynq/
 F:	arch/arm/include/asm/arch-zynq/
 
+ARM ZYNQMP
+M:	Michal Simek <michal.simek@xilinx.com>
+S:	Maintained
+F:	arch/arm/cpu/armv8/zynqmp/
+F:	arch/arm/include/asm/arch-zynqmp/
+
 AVR32
 M:	Andreas Bießmann <andreas.devel@googlemail.com>
 S:	Maintained