ARM64: Move HUSH enabling from board file to defconfig

Simplify board config file.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/xilinx_zynqmp_ep_defconfig b/configs/xilinx_zynqmp_ep_defconfig
index a1f3580..91ae10a 100644
--- a/configs/xilinx_zynqmp_ep_defconfig
+++ b/configs/xilinx_zynqmp_ep_defconfig
@@ -6,6 +6,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="zynqmp-ep108"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
+CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="ZynqMP> "
 # CONFIG_CMD_CONSOLE is not set
 # CONFIG_CMD_IMLS is not set