cbfs: Add API to locate a file from specific region

This patch adds an API to find file by name from
any specific region of fmap.

Change-Id: Iabe785a6434937be6a57c7009882a0d68f6c8ad4
Signed-off-by: Pratik Prajapati <pratikkumar.v.prajapati@intel.com>
Reviewed-on: https://review.coreboot.org/17664
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cbfs.h

@@ -34,6 +34,9 @@ int cbfs_boot_locate(struct cbfsf *fh, const char *name, uint32_t *type);
  * leaking mappings are a no-op. Returns NULL on error, else returns
  * the mapping and sets the size of the file. */
 void *cbfs_boot_map_with_leak(const char *name, uint32_t type, size_t *size);
+/* Locate file in a specific region of fmap. Return 0 on success. < 0 on error*/
+int cbfs_locate_file_in_region(struct cbfsf *fh, const char *region_name,
+		const char *name, uint32_t *type);
 /* Load a struct file from CBFS into a buffer. Returns amount of loaded
  * bytes on success or 0 on error. File will get decompressed as necessary.
  * Same decompression requirements as cbfs_load_and_decompress(). */