[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/au1000/common/time.c b/arch/mips/au1000/common/time.c
index 7e988b0..7fbea1b 100644
--- a/arch/mips/au1000/common/time.c
+++ b/arch/mips/au1000/common/time.c
@@ -383,7 +383,7 @@
 }
 #endif
 
-void __init au1xxx_timer_setup(struct irqaction *irq)
+void __init plat_timer_setup(struct irqaction *irq)
 {
 	unsigned int est_freq;