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/omap35_logic_defconfig b/configs/omap35_logic_defconfig
index d6ca3c2..9d69cc5 100644
--- a/configs/omap35_logic_defconfig
+++ b/configs/omap35_logic_defconfig
@@ -33,6 +33,7 @@
 CONFIG_SPL_FALCON_BOOT_MMCSD=y
 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR=0x1700
 CONFIG_SYS_PROMPT="OMAP Logic # "
+CONFIG_SYS_MAXARGS=64
 # CONFIG_CMD_IMI is not set
 CONFIG_CMD_SPL=y
 CONFIG_CMD_SPL_NAND_OFS=0x240000