zynqmp: Define ep config for ZynqMP

Define a new config "zynqmp_ep" for ZynqMP instead
of xilinx_zynqmp. This defconfig supports all emulation
platforms of ZynqMP. Also renamed TARGET_XILINX_ZYNQMP
to ARCH_ZYNQMP.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d6b06e6..36aa4e9 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -681,7 +681,7 @@
 	select DM_SPI
 	select DM_SPI_FLASH
 
-config TARGET_XILINX_ZYNQMP
+config ARCH_ZYNQMP
 	bool "Support Xilinx ZynqMP Platform"
 	select ARM64