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/sagem_f@st1704_ram_defconfig b/configs/sagem_f@st1704_ram_defconfig
index 4aff0f3..875ae21 100644
--- a/configs/sagem_f@st1704_ram_defconfig
+++ b/configs/sagem_f@st1704_ram_defconfig
@@ -16,6 +16,7 @@
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_OF_STDOUT_VIA_ALIAS=y
 CONFIG_DISPLAY_CPUINFO=y
+CONFIG_SYS_MALLOC_BOOTPARAMS=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="F@ST1704 # "
 CONFIG_SYS_MAXARGS=24