Input: trackpoint - enable Synaptics trackpoints

Add Synaptics IDs in trackpoint_start_protocol() to mark them as valid.

Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Fixes: 6c77545a

 ("Input: trackpoint - add new trackpoint variant IDs")
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Tested-by: Harry Cutts <hcutts@chromium.org>
Link: https://lore.kernel.org/r/20200924053013.1056953-1-vincent.huang@tw.synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>