Convert CONFIG_SYS_BOOTPARAMS_LEN to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_BOOTPARAMS_LEN

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/stmark2_defconfig b/configs/stmark2_defconfig
index e56ca93..dfec23e 100644
--- a/configs/stmark2_defconfig
+++ b/configs/stmark2_defconfig
@@ -16,6 +16,7 @@
 CONFIG_USE_BOOTCOMMAND=y
 CONFIG_BOOTCOMMAND="sf probe 0:1 50000000; sf read ${loadaddr} 0x100000 ${kern_size}; bootm ${loadaddr}"
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_SYS_MALLOC_BOOTPARAMS=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMDLINE_EDITING is not set
 CONFIG_SYS_PROMPT="stmark2 $ "