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/display5_defconfig b/configs/display5_defconfig
index fa271b2..e4b6721 100644
--- a/configs/display5_defconfig
+++ b/configs/display5_defconfig
@@ -49,6 +49,7 @@
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x20000
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="display5 > "
+CONFIG_SYS_MAXARGS=32
 CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_ELF is not set
 CONFIG_CMD_SPL=y