Drop gld linker usage on SunOS

This is required to be removed on SmartOS (Illumos).
As of now there are no alternative supported SunOS distributions.

Signed-off-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

configure

@@ -746,7 +746,6 @@ SunOS)
   solaris="yes"
   make="${MAKE-gmake}"
   install="${INSTALL-ginstall}"
-  ld="gld"
   smbd="${SMBD-/usr/sfw/sbin/smbd}"
   if test -f /usr/include/sys/soundcard.h ; then
     audio_drv_list="oss"