83xx: Replace CONFIG_MPC83XX with CONFIG_MPC83xx

Use the standard lowercase "xx" capitalization that other Freescale
architectures use for CPU defines to prevent confusion and errors

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/doc/README.mpc8349itx b/doc/README.mpc8349itx
index 7f24623..48bbd50 100644
--- a/doc/README.mpc8349itx
+++ b/doc/README.mpc8349itx
@@ -88,7 +88,7 @@
 
 	include/configs/MPC8349ITX.h
 
-	CONFIG_MPC83XX		MPC83xx family
+	CONFIG_MPC83xx		MPC83xx family
 	CONFIG_MPC8349		MPC8349 specific
 	CONFIG_MPC8349ITX		MPC8349E-mITX
 	CONFIG_MPC8349ITXGP		MPC8349E-mITX-GP