cbfs: Allow access to CBFS without a header

In some cases CBFS does not start with a header but is just a collection
of files. It is possible to support this so long as the size of the CBFS
is provided.

Update the cbfs_init_mem() function to support this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/fsp2/fsp_init.c b/arch/x86/lib/fsp2/fsp_init.c
index 85cae54..5afdce1 100644
--- a/arch/x86/lib/fsp2/fsp_init.c
+++ b/arch/x86/lib/fsp2/fsp_init.c
@@ -84,7 +84,8 @@
 	struct cbfs_priv *cbfs;
 	int ret;
 
-	ret = cbfs_init_mem(map_base + cbfs_base, &cbfs);
+	ret = cbfs_init_mem(map_base + cbfs_base, CBFS_SIZE_UNKNOWN, true,
+			    &cbfs);
 	if (ret)
 		return ret;
 	if (!ret) {