Convert CONFIG_SYS_MAXARGS to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_MAXARGS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/xilinx_zynqmp_mini_emmc0_defconfig b/configs/xilinx_zynqmp_mini_emmc0_defconfig
index b405277..d220e58 100644
--- a/configs/xilinx_zynqmp_mini_emmc0_defconfig
+++ b/configs/xilinx_zynqmp_mini_emmc0_defconfig
@@ -24,6 +24,7 @@
 CONFIG_CLOCKS=y
 # CONFIG_CMDLINE_EDITING is not set
 # CONFIG_AUTO_COMPLETE is not set
+CONFIG_SYS_MAXARGS=64
 # CONFIG_CMD_BDI is not set
 # CONFIG_CMD_CONSOLE is not set
 # CONFIG_CMD_BOOTD is not set