Add support for ISDv4 0x12C tablet

Signed-off-by: Jason Gerecke <killertofu@gmail.com>
ISDv4 touch query timeout should be non-fatal

Both the wacom_w8001 and isdv4.c drivers assume that a tablet /may/
respond to the touchquery packet with silence. This assumption does
not carry over to tools-shared.c, and may cause pen-only tablet PC
users trouble with isdv4-serial-inputattach.

Signed-off-by: Jason Gerecke <killertofu@gmail.com>
Tested-by: Anshul Sirur <vixus0@gmail.com>