scons: remove all libudev references

Analogous to previous automake/autoconf commit.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Axel Davy <axel.davy@ens.fr>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/loader/SConscript

@@ -8,10 +8,6 @@ env.Prepend(CPPPATH = [
     '#include'
 ])
 
-if env['udev']:
-    env.PkgUseModules('UDEV')
-    env.Append(CPPDEFINES = ['HAVE_LIBUDEV'])
-
 if env['drm']:
     env.PkgUseModules('DRM')
     env.Append(CPPDEFINES = ['HAVE_LIBDRM'])