sh: intc - add single bitmap register support

This patch adds single bitmap register support to intc. The current
code only handles 16 and 32 bit registers where a set bit means
interrupt enabled, but this is easy to extend in the future.

The INTC_IRQ() macro is also added to provide a way to hook in
interrupt controllers for FPGAs in boards or companion chips.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

include/asm-sh/hw_irq.h

@@ -49,6 +49,7 @@ struct intc_vect {
 };
 
 #define INTC_VECT(enum_id, vect) { enum_id, vect }
+#define INTC_IRQ(enum_id, irq) INTC_VECT(enum_id, irq2evt(irq))
 
 struct intc_prio {
 	intc_enum enum_id;