parisc: Bump 64-bit IRQ stack size to 64 KB

Bump 64-bit IRQ stack size to 64 KB.

I had a kernel IRQ stack overflow on the mx3210 debian buildd machine.  This patch increases the
64-bit IRQ stack size to 64 KB.  The 64-bit stack size needs to be larger than the 32-bit stack
size since registers are twice as big.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: NHelge Deller <deller@gmx.de>

arch/parisc/kernel/irq.c

@@ -373,7 +373,11 @@ static inline int eirr_to_irq(unsigned long eirr)
 /*
  * IRQ STACK - used for irq handler
  */
+#ifdef CONFIG_64BIT
+#define IRQ_STACK_SIZE      (4096 << 4) /* 64k irq stack size */
+#else
 #define IRQ_STACK_SIZE      (4096 << 3) /* 32k irq stack size */
+#endif
 
 union irq_stack_union {
 	unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];