usb: typec: tcpm: Fix misuses of AMS invocation

commit 80137c18 upstream.

tcpm_ams_start is used to initiate an AMS as well as checking Collision
Avoidance conditions but not for flagging passive AMS (initiated by the
port partner). Fix the misuses of tcpm_ams_start in tcpm_pd_svdm.

ATTENTION doesn't need responses so the AMS flag is not needed here.

Fixes: 0bc3ee92

 ("usb: typec: tcpm: Properly interrupt VDM AMS")
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210601123151.3441914-5-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>