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/goflexhome_defconfig b/configs/goflexhome_defconfig
index 3d5fd83..27b7374 100644
--- a/configs/goflexhome_defconfig
+++ b/configs/goflexhome_defconfig
@@ -21,6 +21,7 @@
 CONFIG_CONSOLE_MUX=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_SYS_PROMPT="GoFlexHome> "
+CONFIG_SYS_MAXARGS=32
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_NAND=y
 CONFIG_CMD_SATA=y