powerpc/gc/wii: Remove get_irq_desc()

Fix the following build failures:

arch/powerpc/platforms/embedded6xx/flipper-pic.c: In function 'flipper_pic_map':
arch/powerpc/platforms/embedded6xx/flipper-pic.c:105: error: implicit declaration of function 'get_irq_desc'

arch/powerpc/platforms/embedded6xx/hlwd-pic.c: In function 'hlwd_pic_map':
arch/powerpc/platforms/embedded6xx/hlwd-pic.c:98: error: implicit declaration of function 'get_irq_desc'

These failures are caused by the changes introduced in commit
"powerpc: Remove get_irq_desc()". The reason these drivers were not
updated is that they weren't merged yet.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/embedded6xx/flipper-pic.c

@@ -102,7 +102,7 @@ static int flipper_pic_map(struct irq_host *h, unsigned int virq,
 			   irq_hw_number_t hwirq)
 {
 	set_irq_chip_data(virq, h->host_data);
-	get_irq_desc(virq)->status |= IRQ_LEVEL;
+	irq_to_desc(virq)->status |= IRQ_LEVEL;
 	set_irq_chip_and_handler(virq, &flipper_pic, handle_level_irq);
 	return 0;
 }

arch/powerpc/platforms/embedded6xx/hlwd-pic.c

@@ -95,7 +95,7 @@ static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
 			   irq_hw_number_t hwirq)
 {
 	set_irq_chip_data(virq, h->host_data);
-	get_irq_desc(virq)->status |= IRQ_LEVEL;
+	irq_to_desc(virq)->status |= IRQ_LEVEL;
 	set_irq_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
 	return 0;
 }