powerpc: Remove get_irq_desc()

get_irq_desc() is a powerpc-specific version of irq_to_desc(). That
is reason enough to remove it, but it also doesn't know about sparse
irq_desc support which irq_to_desc() does (when we enable it).

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/sysdev/cpm2_pic.c b/arch/powerpc/sysdev/cpm2_pic.c
index 78f1f7c..722cf72 100644
--- a/arch/powerpc/sysdev/cpm2_pic.c
+++ b/arch/powerpc/sysdev/cpm2_pic.c
@@ -115,11 +115,13 @@
 
 static void cpm2_end_irq(unsigned int virq)
 {
+	struct irq_desc *desc;
 	int	bit, word;
 	unsigned int irq_nr = virq_to_hw(virq);
 
-	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
-			&& irq_desc[irq_nr].action) {
+	desc = irq_to_desc(irq_nr);
+	if (!(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS))
+			&& desc->action) {
 
 		bit = irq_to_siubit[irq_nr];
 		word = irq_to_siureg[irq_nr];
@@ -138,7 +140,7 @@
 static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
 {
 	unsigned int src = virq_to_hw(virq);
-	struct irq_desc *desc = get_irq_desc(virq);
+	struct irq_desc *desc = irq_to_desc(virq);
 	unsigned int vold, vnew, edibit;
 
 	if (flow_type == IRQ_TYPE_NONE)
@@ -210,7 +212,7 @@
 {
 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
 
-	get_irq_desc(virq)->status |= IRQ_LEVEL;
+	irq_to_desc(virq)->status |= IRQ_LEVEL;
 	set_irq_chip_and_handler(virq, &cpm2_pic, handle_level_irq);
 	return 0;
 }