Use GNU ld to link roms on OpenSolaris

OpenSolaris ld seems to miss the equivalent of GNU ld's "-Ttext 0".
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

configure

@@ -299,6 +299,7 @@ SunOS)
   solaris="yes"
   make="gmake"
   install="ginstall"
+  ld="gld"
   needs_libsunmath="no"
   solarisrev=`uname -r | cut -f2 -d.`
   # have to select again, because `uname -m` returns i86pc