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/vocore2_defconfig b/configs/vocore2_defconfig
index 8676554..6240e47 100644
--- a/configs/vocore2_defconfig
+++ b/configs/vocore2_defconfig
@@ -33,6 +33,7 @@
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_NOR_SUPPORT=y
 CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=64
 CONFIG_CMD_LICENSE=y
 # CONFIG_BOOTM_NETBSD is not set
 # CONFIG_BOOTM_PLAN9 is not set