usb: typec: intel_pmc_mux: Configure cable generation value for USB4

USB4 specification chapter 3 indicates that cable data rates have to be
rounded for USB4 device to operate as USB4.
With that configure cable generation value to use rounded data rates for
USB4.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Utkarsh Patel <utkarsh.h.patel@intel.com>
Link: https://lore.kernel.org/r/20201209042408.23079-2-utkarsh.h.patel@intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/mux/intel_pmc_mux.c

@@ -327,6 +327,11 @@ pmc_usb_mux_usb4(struct pmc_usb_port *port, struct typec_mux_state *state)
 		fallthrough;
 	default:
 		req.mode_data |= PMC_USB_ALTMODE_ACTIVE_CABLE;
+
+		/* Configure data rate to rounded in the case of Active TBT3
+		 * and USB4 cables.
+		 */
+		req.mode_data |= PMC_USB_ALTMODE_TBT_GEN(1);
 		break;
 	}