[SPARC64]: More sensible udelay implementation.

Take a page from the powerpc folks and just calculate the
delay factor directly.

Since frequency scaling chips use a system-tick register,
the value is going to be the same system-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>

include/asm-sparc64/cpudata.h

@@ -19,7 +19,7 @@ typedef struct {
 	unsigned int	__softirq_pending; /* must be 1st, see rtrap.S */
 	unsigned int	__pad0;
 	unsigned long	clock_tick;	/* %tick's per second */
-	unsigned long	udelay_val;
+	unsigned long	__pad;
 	unsigned int	__pad1;
 	unsigned int	__pad2;