Add touch surface resolution information. The size of the touch surfaces
has been determined to the hundredth of a mm.

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Michael Poole <mdpoole@troilus.org>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
[jkosina@suse.cz: update comments and commit message]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>