irqchip: spear_shirq: Fix interrupt offset

The ras3 block on spear320 claims to have 3 interrupts. In fact it has
one and 6 reserved interrupts. Account the 6 reserved to this block so
it has 7 interrupts total. That matches the datasheet and the device
tree entries.

Broken since commit 80515a5a(ARM: SPEAr3xx: shirq: simplify and move
the shared irq multiplexor to DT). Testing is overrated....
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20140619212712.872379208@linutronix.de
Fixes: 80515a5a ('ARM: SPEAr3xx: shirq: simplify and move the shared irq multiplexor to DT')
Cc: <stable@vger.kernel.org> # v3.8+
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

drivers/irqchip/spear-shirq.c

@@ -125,7 +125,7 @@ static struct spear_shirq spear320_shirq_ras2 = {
 };
 
 static struct spear_shirq spear320_shirq_ras3 = {
-	.irq_nr = 3,
+	.irq_nr = 7,
 	.irq_bit_off = 0,
 	.invalid_irq = 1,
 	.regs = {