ata: pata_parport: remove typedef struct PIA

Remove typedef struct PIA and use struct pi_adapter directly.
Fix formatting (excessive spaces) while at it.

Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Ondrej Zary <linux@zary.sk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>