patch 8.1.1225: cannot create a pty to use with :terminal on FreeBSD

Problem:    Cannot create a pty to use with :terminal on FreeBSD.
Solution:   Add support for posix_openpt(). (Ozaki Kiichi, closes #4306,
            closes #4289)
diff --git a/src/version.c b/src/version.c
index ae93dc3..7c42d18 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1225,
+/**/
     1224,
 /**/
     1223,