The ncr5380 driver is included by multiple board specific
drivers, which may or may not use the interrupt handler.
The oak variant doesn't, and should set the DONT_USE_INTR
macro.

Without this patch, building rpc_defconfig results in:

drivers/scsi/arm/../NCR5380.c:1160:20: warning: 'oakscsi_intr' defined but not used [-Wunused-function]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-scsi@vger.kernel.org