ncr5380: Add support for HP C2502

HP C2502 cards (based on 53C400A chips) use different magic numbers for
software-based I/O address configuration than other cards.
The configuration is also extended to allow setting the IRQ.

Move the configuration to a new function magic_configure() and move
magic the magic numbers into an array. Add new magic numbers for these
HP cards and hp_c2502 module parameter to use them, e.g.:
modprobe g_NCR5380 ncr_irq=7 ncr_addr=0x280 hp_c2502=1

Tested with HP C2502 and DTCT-436P.

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