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/crs305-1g-4s_defconfig b/configs/crs305-1g-4s_defconfig
index 54f5268..d276997 100644
--- a/configs/crs305-1g-4s_defconfig
+++ b/configs/crs305-1g-4s_defconfig
@@ -21,6 +21,7 @@
 CONFIG_USE_PREBOOT=y
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=96
 CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_MTD=y