irq_domain/powerpc: Replace custom xlate functions with library functions

This patch converts a number of the powerpc drivers to use the common library
of irq_domain xlate functions, dropping a bunch of lines in the process.

v5: - Remove tsi108 changes from patch

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/powerpc/sysdev/cpm2_pic.c b/arch/powerpc/sysdev/cpm2_pic.c
index 8c9fc9c..d3be961 100644
--- a/arch/powerpc/sysdev/cpm2_pic.c
+++ b/arch/powerpc/sysdev/cpm2_pic.c
@@ -224,21 +224,9 @@
 	return 0;
 }
 
-static int cpm2_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
-			    const u32 *intspec, unsigned int intsize,
-			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
-{
-	*out_hwirq = intspec[0];
-	if (intsize > 1)
-		*out_flags = intspec[1];
-	else
-		*out_flags = IRQ_TYPE_NONE;
-	return 0;
-}
-
 static const struct irq_domain_ops cpm2_pic_host_ops = {
 	.map = cpm2_pic_host_map,
-	.xlate = cpm2_pic_host_xlate,
+	.xlate = irq_domain_xlate_onetwocell,
 };
 
 void cpm2_pic_init(struct device_node *node)