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/jethub_j100_defconfig b/configs/jethub_j100_defconfig
index 63c5329..d0070bb 100644
--- a/configs/jethub_j100_defconfig
+++ b/configs/jethub_j100_defconfig
@@ -17,6 +17,7 @@
 CONFIG_OF_BOARD_SETUP=y
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_MISC_INIT_R=y
+CONFIG_SYS_MAXARGS=32
 # CONFIG_CMD_BDI is not set
 # CONFIG_CMD_IMI is not set
 CONFIG_CMD_EEPROM=y