thunderbolt: Handle ERR_LOCK notification

If the USB4 router downstream port is locked, sending configuration
packet to a router below it causes ERR_LOCK to be sent. Instead of warn
splat about unknown error we log the error (just warning level) and
return -EACCESS instead. The idea is that we may want to do something
when such error code is received, like perform unlock.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>