Input: ams_delta_serio: Get FIQ buffer from platform_data

Instead of exporting the FIQ buffer symbol to be used in
ams-delta-serio driver, pass it to the driver as platform_data.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>