Input: synaptics - print firmware ID and board number at init

Read the Firmware ID and Board Number from a synaptics device at init
and display them in the system log.

Device behavior is very board and firmware dependent.
It may prove useful for users to include this information when providing
bug reports or other feedback.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>