sh: Convert Dreamcast support from hw_interrupt_type to irq_chip

Switch the dreamcast IRQ code over to the irq_chip way of doing things,
so that we can set GENERIC_HARDIRQS_NO__DO_IRQ for all SuperH boards.

Also, whilst I'm here change some things to make checkpatch.pl happy:
	- Indent with tabs, not with spaces
	- Include <linux/io.h>, not <asm/io.h>
	- Fix the multi-line comment style
	- Fix some typos in the comments

Tested-by: Adrian McMenamin <adrian@newgolddream.dyndns.info>
Signed-off-by: Matt Fleming <mjf@gentoo.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/boards/mach-dreamcast/setup.c b/arch/sh/boards/mach-dreamcast/setup.c
index 7d944fc..d1bee48 100644
--- a/arch/sh/boards/mach-dreamcast/setup.c
+++ b/arch/sh/boards/mach-dreamcast/setup.c
@@ -28,7 +28,7 @@
 #include <asm/machvec.h>
 #include <mach/sysasic.h>
 
-extern struct hw_interrupt_type systemasic_int;
+extern struct irq_chip systemasic_int;
 extern void aica_time_init(void);
 extern int gapspci_init(void);
 extern int systemasic_irq_demux(int);
@@ -47,7 +47,8 @@
 
 	/* Assign all virtual IRQs to the System ASIC int. handler */
 	for (i = HW_EVENT_IRQ_BASE; i < HW_EVENT_IRQ_MAX; i++)
-		irq_desc[i].chip = &systemasic_int;
+		set_irq_chip_and_handler(i, &systemasic_int,
+					 handle_level_irq);
 
 	board_time_init = aica_time_init;