Input: synaptics-rmi4 - switch to reduced reporting mode

When the distance thresholds are set the controller must be in reduced
reporting mode for them to have any effect on the interrupt generation.
This has a potentially large impact on the number of events the host
needs to process.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
Link: https://lore.kernel.org/r/20200120111628.18376-1-l.stach@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>