usb: typec: tcpm: Respond Not_Supported if no snk_vdo

usb: typec: tcpm: Respond Not_Supported if no snk_vdo

If snk_vdo is not populated from fwnode, it implies the port does not
support responding to SVDM commands. Not_Supported Message shall be sent
if the contract is in PD3. And for PD2, the port shall ignore the
commands.

Fixes: 193a68011fdc ("staging: typec: tcpm: Respond to Discover Identity commands")
Cc: stable <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]>
Acked-by: Heikki Krogerus <[email protected]>
Signed-off-by: Kyle Tso <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>