mpc8xxx: LCRR[CLKDIV] is sometimes five bits

On newer CPUs, 8536, 8572, and 8610, the CLKDIV field of LCRR is five bits
instead of four.

In order to avoid an ifdef, LCRR_CLKDIV is set to 0x1f on all systems.  It
should be safe as the fifth bit was defined as reserved and set to 0.

Code that was using a hard coded 0x0f is changed to use LCRR_CLKDIV.

Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Jon Loeliger <jdl@freescale.com>
diff --git a/board/pm854/pm854.c b/board/pm854/pm854.c
index fed0ed4..5353d73 100644
--- a/board/pm854/pm854.c
+++ b/board/pm854/pm854.c
@@ -150,7 +150,7 @@
 	 */
 
 	get_sys_info(&sysinfo);
-	clkdiv = lbc->lcrr & 0x0f;
+	clkdiv = lbc->lcrr & LCRR_CLKDIV;
 	lbc_hz = sysinfo.freqSystemBus / 1000000 / clkdiv;
 
 	if (lbc_hz < 66) {