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/tplink_wdr4300_defconfig b/configs/tplink_wdr4300_defconfig
index c8f97be..62d9ec2 100644
--- a/configs/tplink_wdr4300_defconfig
+++ b/configs/tplink_wdr4300_defconfig
@@ -16,6 +16,7 @@
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=32
 # CONFIG_CMD_ELF is not set
 # CONFIG_CMD_XIMG is not set
 CONFIG_CMD_MEMTEST=y