ata: pata_cs5520: Add a couple of missing param descriptions

Fixes the following W=1 kernel build warning(s):

 drivers/ata/pata_cs5520.c:61: warning: Function parameter or member 'pio' not described in 'cs5520_set_timings'
 drivers/ata/pata_cs5520.c:257: warning: Function parameter or member 'mesg' not described in 'cs5520_pci_device_suspend'

Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>