Move initf_malloc() to a common place

To allow this function to be used from SPL, move it to the malloc()
code.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/dlmalloc.c

@@ -3261,6 +3261,17 @@ int mALLOPt(param_number, value) int param_number; int value;
   }
 }
 
+int initf_malloc(void)
+{
+#ifdef CONFIG_SYS_MALLOC_F_LEN
+	assert(gd->malloc_base);	/* Set up by crt0.S */
+	gd->malloc_limit = CONFIG_SYS_MALLOC_F_LEN;
+	gd->malloc_ptr = 0;
+#endif
+
+	return 0;
+}
+
 /*
 
 History: