HID: rmi: The address of query8 must be calculated based on which query registers are present

If a touchpad does not report relative data then query 6 will not be present and the address
of query 8 will be one less. This patches calculates the location of query 8 instead of
hardcoding the offset.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>