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/arch/arm/Kconfig b/arch/arm/Kconfig
index 7a2f91c..5e255cb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -592,6 +592,10 @@
 	select CPU_V7
 	select SUPPORT_SPL
 
+config TARGET_XILINX_ZYNQMP
+	bool "Support Xilinx ZynqMP Platform"
+	select ARM64
+
 config TEGRA
 	bool "NVIDIA Tegra"
 	select SUPPORT_SPL
@@ -840,6 +844,7 @@
 source "board/wandboard/Kconfig"
 source "board/woodburn/Kconfig"
 source "board/xaeniax/Kconfig"
+source "board/xilinx/zynqmp/Kconfig"
 source "board/zipitz2/Kconfig"
 
 source "arch/arm/Kconfig.debug"