Add FreeBSD-specific PAM file

Signed-off-by: AnErrupTion <anerruption@disroot.org>

res/pam.d/ly-freebsd

@@ -0,0 +1,8 @@
+#%PAM-1.0
+
+# OpenPAM (used in FreeBSD) doesn't support prepending "-" for ignoring missing
+# modules.
+auth       include      login
+account    include      login
+password   include      login
+session    include      login