ata: pata_parport-bpck6: remove ppc6_close

ppc6_close does not do anything except calling ppc6_deselect. Remove
ppc6_close and call ppc6_deselect directly.

Signed-off-by: Ondrej Zary <linux@zary.sk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>