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

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.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>