aha1542: Split aha1542_out

aha1542_out are in fact two separate functions.
Split them into aha1542_out and aha1542_outb to simplify the code.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>