Input: iforce - allow callers supply data buffer when fetching device IDs

We want to move buffer handling into transport layers as the properties of
buffers (DMA-safety, alignment, etc) are different for different
transports. To allow this, let's allow caller to specify their own buffers
for the results of iforce_get_id_packet() and let transport drivers to
figure what buffers they need to use for transfers.

Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>