scons: Do not build EGL on Solaris.

The current EGL headers do not support Solaris.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Brian Paul <brianp@vmware.com>
diff --git a/src/SConscript b/src/SConscript
index ba6be0b..777ad23 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -24,7 +24,7 @@
 if not env['embedded']:
     if env['platform'] not in ['windows', 'darwin', 'haiku']:
         SConscript('glx/SConscript')
-    if env['platform'] not in ['darwin', 'haiku']:
+    if env['platform'] not in ['darwin', 'haiku', 'sunos']:
         SConscript('egl/main/SConscript')
     if env['platform'] not in ['darwin']:
         SConscript('glu/sgi/SConscript')