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/configs/mpc8308_p1m.h b/include/configs/mpc8308_p1m.h
index 035a1b6..aa681f0 100644
--- a/include/configs/mpc8308_p1m.h
+++ b/include/configs/mpc8308_p1m.h
@@ -30,6 +30,7 @@
  */
 #define CONFIG_E300		1 /* E300 family */
 #define CONFIG_MPC83xx		1 /* MPC83xx family */
+#define CONFIG_MPC830x		1 /* MPC830x family */
 #define CONFIG_MPC8308		1 /* MPC8308 CPU specific */
 #define CONFIG_MPC8308_P1M	1 /* mpc8308_p1m board specific */