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/j721e_hs_evm_r5_defconfig b/configs/j721e_hs_evm_r5_defconfig
index 11b6e1e..7a5867b 100644
--- a/configs/j721e_hs_evm_r5_defconfig
+++ b/configs/j721e_hs_evm_r5_defconfig
@@ -48,6 +48,7 @@
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x80000
 CONFIG_SPL_YMODEM_SUPPORT=y
 CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=64
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_GPT=y
 CONFIG_CMD_MMC=y