lzo: add a function to check the validity of the header

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/linux/lzo.h

@@ -31,6 +31,9 @@ int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
 int lzop_decompress(const unsigned char *src, size_t src_len,
 		    unsigned char *dst, size_t *dst_len);
 
+/* check if the header is valid (based on magic numbers) */
+bool lzop_is_valid_header(const unsigned char *src);
+
 /*
  * Return values (< 0 = Error)
  */