automake: create compat symlinks only for linux systems

The primary users of these are linux developers, although
it can be extended for *BSD and others if needed.

Fixes make install for Cygwin and OpenBSD at least.

v2:
 - Wrap vdpau targets as well.
v3:
 - Fold HAVE_COMPAT_SYMLINKS conditional within install*links.mk

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63269
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Jon TURNEY <jon.turney@dronecode.org.uk> (v1)
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/install-lib-links.mk b/install-lib-links.mk
index 2707eb8..0e13719 100644
--- a/install-lib-links.mk
+++ b/install-lib-links.mk
@@ -1,6 +1,7 @@
 # Provide compatibility with scripts for the old Mesa build system for
 # a while by putting a link to the driver into /lib of the build tree.
 
+if HAVE_COMPAT_SYMLINKS
 all-local : .libs/install-mesa-links
 
 .libs/install-mesa-links : $(lib_LTLIBRARIES)
@@ -12,3 +13,4 @@
 			ln -f $$f $(top_builddir)/$(LIB_DIR);	\
 		fi;						\
 	done && touch $@
+endif