usb: pd: Add helper macro to get Type C cable speed

Added a helper macro to get the Type C cable speed when provided the
cable VDO.

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/20230920023243.2494410-4-utkarsh.h.patel@intel.com


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