PPC: Create and use CONFIG_HIGH_BATS

Change all code that conditionally operates on high bat
registers (that is, BATs 4-7) to look at CONFIG_HIGH_BATS
instead of the myriad ways this is done now.  Define the option
for every config for which high bats are supported (and
enabled by early boot, on parts where they're not always
enabled)

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
diff --git a/include/configs/ads5121.h b/include/configs/ads5121.h
index c975a24..4226529 100644
--- a/include/configs/ads5121.h
+++ b/include/configs/ads5121.h
@@ -372,6 +372,8 @@
 #define CFG_HID0_FINAL	HID0_ENABLE_MACHINE_CHECK
 #define CFG_HID2	HID2_HBE
 
+#define CONFIG_HIGH_BATS	1	/* High BATs supported */
+
 /*
  * Internal Definitions
  *