w32: Add another pinentry search path

* common/homedir.c (get_default_pinentry_name): Try ../bin/pinentry.exe

--
In an installation layout where GnuPG is installed as a component
of another software it might be useful to have pinentry placed
in a different bin directory without the forced folder name of
Gpg4win.

(cherry picked from commit b4cb91d5fb)

common/homedir.c

@@ -994,6 +994,8 @@ get_default_pinentry_name (int reset)
     /* Try Gpg4win directory (with bin and without.) */
     { w32_rootdir, "\\..\\Gpg4win\\bin\\pinentry.exe" },
     { w32_rootdir, "\\..\\Gpg4win\\pinentry.exe" },
+    /* Try a pinentry in a dir above us */
+    { w32_rootdir, "\\..\\bin\\pinentry.exe" },
     /* Try old Gpgwin directory.  */
     { w32_rootdir, "\\..\\GNU\\GnuPG\\pinentry.exe" },
     /* Try a Pinentry from the common GNU dir.  */