Input: synaptics - relax capability ID checks on newer hardware

Older firmwares fixed the middle byte of the Synaptics capabilities
query to 0x47, but starting with firmware 7.5 the middle byte
represents submodel ID, sometimes also called "dash number".

Reported-and-tested-by: Miroslav Šulc <fordfrog@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>