sandbox: config: Enable pre-relocation malloc()

Enable this for sandbox so that we will be able to use driver model before
relocation.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index 12b69d9..bf2d25c 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -68,8 +68,10 @@
 #define CONFIG_EFI_PARTITION
 
 /*
- * Size of malloc() pool, although we don't actually use this yet.
+ * Size of malloc() pool, before and after relocation
  */
+#define CONFIG_SYS_MALLOC_F_LEN	(1 << 10)
+#define CONFIG_MALLOC_F_ADDR		0x0010000
 #define CONFIG_SYS_MALLOC_LEN		(32 << 20)	/* 32MB  */
 
 #define CONFIG_SYS_HUSH_PARSER