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/sagem_f@st1704_ram_defconfig b/configs/sagem_f@st1704_ram_defconfig
index c06ff63..fd246b1 100644
--- a/configs/sagem_f@st1704_ram_defconfig
+++ b/configs/sagem_f@st1704_ram_defconfig
@@ -18,6 +18,7 @@
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="F@ST1704 # "
+CONFIG_SYS_MAXARGS=24
 CONFIG_CMD_CPU=y
 CONFIG_CMD_LICENSE=y
 # CONFIG_CMD_BOOTD is not set