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/common/Kconfig b/common/Kconfig
index a96842a..84db2e4 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -659,6 +659,18 @@
 	help
 	  Enabling this option calls 'misc_init_r' function
 
+config SYS_MALLOC_BOOTPARAMS
+	bool "Malloc a buffer to use for bootparams"
+	help
+	  In some cases rather than using a known location to store the
+	  bi_boot_params portion of gd we need to allocate it from our malloc pool.
+
+config SYS_BOOTPARAMS_LEN
+	hex "Size of the bootparam buffer to malloc in bytes"
+	depends on SYS_MALLOC_BOOTPARAMS
+	default 0x20000 if MIPS || RCAR_GEN3
+	default 0x10000
+
 config ID_EEPROM
 	bool "Enable I2C connected system identifier EEPROM"
 	help