Add --enable-solaris to descend into solaris-specific build directory.
While it doesn't take a long time to build, this is currently the only
thing in the tree that doesn't work with BSD make, and there's no
reason to build solaris package control files on other systems.
diff --git a/Makefile.am b/Makefile.am
index f6c09a1..96da94f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,7 +2,7 @@
 
 SUBDIRS = lib @ZEBRA@ @BGPD@ @RIPD@ @RIPNGD@ @OSPFD@ @OSPF6D@ \
          @ISISD@ @WATCHQUAGGA@ @VTYSH@ @OSPFCLIENT@ doc m4 @pkgsrcdir@ \
-         redhat solaris
+         redhat @SOLARIS@
 
 DIST_SUBDIRS = lib zebra bgpd ripd ripngd ospfd ospf6d \
 	  isisd watchquagga vtysh ospfclient doc m4 pkgsrc redhat tests \