meson: don't build glx or dri by default on windows

v5: - Move is windows check down to make code more robust

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

meson.build

@@ -320,6 +320,8 @@ if with_glx == 'auto'
     with_glx = 'dri'
   elif with_platform_haiku
     with_glx = 'disabled'
+  elif host_machine.system() == 'windows'
+    with_glx = 'disabled'
   elif with_gallium
     # Even when building just gallium drivers the user probably wants dri
     with_glx = 'dri'