[MIPS] Replace board_timer_setup function pointer by plat_timer_setup.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

---
diff --git a/arch/mips/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c
index aa0d6ff..0a6ee8e 100644
--- a/arch/mips/pmc-sierra/yosemite/setup.c
+++ b/arch/mips/pmc-sierra/yosemite/setup.c
@@ -133,14 +133,13 @@
 	return 0;
 }
 
-void yosemite_timer_setup(struct irqaction *irq)
+void __init plat_timer_setup(struct irqaction *irq)
 {
 	setup_irq(7, irq);
 }
 
 void yosemite_time_init(void)
 {
-	board_timer_setup = yosemite_timer_setup;
 	mips_hpt_frequency = cpu_clock / 2;
 mips_hpt_frequency = 33000000 * 3 * 5;
 }