i965/fs: Allow SIMD16 with control flow on Ivybridge.

The check was designed to forbid it on old generations (Gen5/Ironlake),
not on new ones.  It just works on Gen7/Ivybridge.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/mesa/drivers/dri/i965/brw_fs_visitor.cpp

@@ -1522,7 +1522,7 @@ fs_visitor::visit(ir_if *ir)
 {
    fs_inst *inst;
 
-   if (intel->gen != 6 && c->dispatch_width == 16) {
+   if (intel->gen < 6 && c->dispatch_width == 16) {
       fail("Can't support (non-uniform) control flow on 16-wide\n");
    }