[MIPS] i8253 PIT clocksource and clockevent drivers

Derived from the i386 variant with a few x86 complexities chopped off.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/sgi-ip22/ip22-time.c b/arch/mips/sgi-ip22/ip22-time.c
index a1df1f9..9b9bffd 100644
--- a/arch/mips/sgi-ip22/ip22-time.c
+++ b/arch/mips/sgi-ip22/ip22-time.c
@@ -20,6 +20,7 @@
 
 #include <asm/cpu.h>
 #include <asm/mipsregs.h>
+#include <asm/i8253.h>
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/time.h>
@@ -172,6 +173,9 @@
 		(int) (r4k_tick % (500000 / HZ)));
 
 	mips_hpt_frequency = r4k_tick * HZ;
+
+	if (ip22_is_fullhouse())
+		setup_pit_timer();
 }
 
 /* Generic SGI handler for (spurious) 8254 interrupts */