ncr5380: Implement new eh_bus_reset_handler

NCR5380.c lacks a sane eh_bus_reset_handler. The atari_NCR5380.c code is
much better but it should not throw out the issue queue (that would be
a host reset) and it neglects to set the result code for commands that it
throws out. Fix these bugs and keep the two core drivers in sync.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>