phy_internal: Disable coltest without wishbone

When the wishbone management interface is disabled, disable coltest.

Fixes: b351beb ("Add hub")
Signed-off-by: Sean Anderson <seanga2@gmail.com>

rtl/phy_internal.v

@@ -126,6 +126,7 @@ module phy_internal (
 		assign wb_ack = 0;
 		assign wb_err = wb_cyc && wb_stb;
 		assign loopback = 0;
+		assign coltest = 0;
 		assign descrambler_test = 0;
 		assign link_monitor_test = 0;
 	end endgenerate