[SPARC64]: More entropy in add_timer_randomness.

Based upon a patch from Richard Mortimer.
Signed-off-by: David S. Miller <davem@redhat.com>

drivers/char/random.c

@@ -822,6 +822,11 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
 	} else {
 		time = jiffies;
 	}
+#elif defined (__sparc_v9__)
+	unsigned long tick = tick_ops->get_tick();
+
+	time = (unsigned int) tick;
+	num ^= (tick >> 32UL);
 #else
 	time = jiffies;
 #endif