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.mpc832xemds b/doc/README.mpc832xemds
index b63cc79..9f7409c 100644
--- a/doc/README.mpc832xemds
+++ b/doc/README.mpc832xemds
@@ -83,7 +83,7 @@
 
 	include/configs/MPC832XEPB.h
 
-    CONFIG_MPC83XX	MPC83XX family for MPC8349, MPC8360 and MPC832X
+    CONFIG_MPC83xx	MPC83XX family for MPC8349, MPC8360 and MPC832X
     CONFIG_MPC832X	MPC832X specific
     CONFIG_MPC832XEMDS	MPC832XEMDS board specific