policy_engine: Clear ss_lane_svid in reset_vdm_state()

During insertion of DP adaptor, our target might start in SINK mode
as well. In that case, DP adaptor sends DR_SWAP to change data role
from UFP to DFP. While starting host mode, driver is not clearing
ss_lane_svid variable due to which usb_pd_release_ss_lanes() will
return -EBUSY even though DP client is requesting. Fix the issue by
clearing ss_lane_svid in reset_vdm_state() unconditionally.

Change-Id: I62e775623295d795ad3e203590634f669cbf7537
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>