cleanup: introduce CONFIG_MPC830x

Introduce a new configuration token CONFIG_MPC830x to be shared among
mpc8308 and mpc8309. Define it for existing 8308 boards, and refactor
existing common code so to make future introduction of 8309 simpler.

Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/include/mpc83xx.h b/include/mpc83xx.h
index a78f1a2..7a19740 100644
--- a/include/mpc83xx.h
+++ b/include/mpc83xx.h
@@ -969,7 +969,7 @@
  */
 #define CSCONFIG_EN			0x80000000
 #define CSCONFIG_AP			0x00800000
-#if defined(CONFIG_MPC8308) || defined(CONFIG_MPC831x)
+#if defined(CONFIG_MPC830x) || defined(CONFIG_MPC831x)
 #define CSCONFIG_ODT_RD_NEVER		0x00000000
 #define CSCONFIG_ODT_RD_ONLY_CURRENT	0x00100000
 #define CSCONFIG_ODT_RD_ONLY_OTHER_CS	0x00200000