Fix path of pkgconfig files passed to gpgrt-config.

--- configure.orig	2024-03-06 13:53:12 UTC
+++ configure
@@ -15047,7 +15047,7 @@ fi
     # Get the prefix of gpgrt-config assuming it's something like:
     #   <PREFIX>/bin/gpgrt-config
     gpgrt_prefix=${GPGRT_CONFIG%/*/*}
-    possible_libdir1=${gpgrt_prefix}/lib
+    possible_libdir1=${gpgrt_prefix}/libdata
     # Determine by using system libdir-format with CC, it's like:
     #   Normal style: /usr/lib
     #   GNU cross style: /usr/<triplet>/lib