MIPS: SNI: Fix SCSI interrupt

On RM400(a20r) machines ISA and SCSI interrupts share the same interrupt
line. Commit 49e6e07e3c80 ("MIPS: pass non-NULL dev_id on shared
request_irq()") accidently dropped the IRQF_SHARED bit, which breaks
registering SCSI interrupt. Put back IRQF_SHARED and add dev_id for
ISA interrupt.

Fixes: 49e6e07e3c80 ("MIPS: pass non-NULL dev_id on shared request_irq()")
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
diff --git a/arch/mips/sni/a20r.c b/arch/mips/sni/a20r.c
index 0ecffb6..b09dc84 100644
--- a/arch/mips/sni/a20r.c
+++ b/arch/mips/sni/a20r.c
@@ -222,8 +222,8 @@ void __init sni_a20r_irq_init(void)
 		irq_set_chip_and_handler(i, &a20r_irq_type, handle_level_irq);
 	sni_hwint = a20r_hwint;
 	change_c0_status(ST0_IM, IE_IRQ0);
-	if (request_irq(SNI_A20R_IRQ_BASE + 3, sni_isa_irq_handler, 0, "ISA",
-			NULL))
+	if (request_irq(SNI_A20R_IRQ_BASE + 3, sni_isa_irq_handler,
+			IRQF_SHARED, "ISA", sni_isa_irq_handler))
 		pr_err("Failed to register ISA interrupt\n");
 }