85xx/86xx: Rename ext_refrec to timing_cfg_3 to match docs

All the 85xx and 86xx UM describe the register as timing_cfg_3
not as ext_refrec.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc85xx/spd_sdram.c b/cpu/mpc85xx/spd_sdram.c
index 435458a..e3a8249 100644
--- a/cpu/mpc85xx/spd_sdram.c
+++ b/cpu/mpc85xx/spd_sdram.c
@@ -610,8 +610,8 @@
 	/*
 	 * Sneak in some Extended Refresh Recovery.
 	 */
-	ddr->ext_refrec = (trfc_high << 16);
-	debug("DDR: ext_refrec = 0x%08x\n", ddr->ext_refrec);
+	ddr->timing_cfg_3 = (trfc_high << 16);
+	debug("DDR: timing_cfg_3 = 0x%08x\n", ddr->timing_cfg_3);
 
 	ddr->timing_cfg_1 =
 	    (0