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/uc101.h b/include/configs/uc101.h
index dc1d7e1..042750e 100644
--- a/include/configs/uc101.h
+++ b/include/configs/uc101.h
@@ -40,6 +40,8 @@
 
 #define CONFIG_BOARD_EARLY_INIT_R
 
+#define CONFIG_HIGH_BATS	1	/* High BATs supported 			*/
+
 /*
  * Serial console configuration
  */