ncr5380: Merge changes from atari_NCR5380.c

In the past, NCR5380.c was overlooked by those working on atari_NCR5380.c
and this caused needless divergence. All of the changes in this patch were
taken from atari_NCR5380.c.

This removes some unimportant discrepancies between the two core driver
forks so that 'diff' can be used to reveal the important ones, to
facilitate reunification.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>