rsa: Add rsa_verify_openssl() to use openssl for host builds

rsa_verify_openssl() is used in lib/rsa/rsa-verify.c to authenticate data
when building host tools.

Signed-off-by: Paul HENRYS <paul.henrys_ext@softathome.com>

include/image.h

@@ -1688,6 +1688,24 @@ struct sig_header_s {
  */
 int image_pre_load(ulong addr);
 
+#if defined(USE_HOSTCC)
+/**
+ * rsa_verify_openssl() - Verify a signature against some data with openssl API
+ *
+ * Verify a RSA PKCS1.5/PSS signature against an expected hash.
+ *
+ * @info:		Specifies the key and algorithms
+ * @region:		Pointer to the input data
+ * @region_count:	Number of region
+ * @sig:		Signature
+ * @sig_len:		Number of bytes in the signature
+ * Return: 0 if verified, -ve on error
+ */
+int rsa_verify_openssl(struct image_sign_info *info,
+		       const struct image_region region[], int region_count,
+		       uint8_t *sig, uint sig_len);
+#endif
+
 /**
  * fit_image_verify_required_sigs() - Verify signatures marked as 'required'
  *