Makefile: move all Power Architecture boards into boards.cfg

Clean up Makefile, and drop a lot of the config.mk files on the way.

We now also automatically pick all boards that are listed in
boards.cfg (and with all configurations), so we can drop the redundant
entries from MAKEALL to avoid building these twice.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/include/configs/BAB7xx.h b/include/configs/BAB7xx.h
index 555145e..0cfd5d9 100644
--- a/include/configs/BAB7xx.h
+++ b/include/configs/BAB7xx.h
@@ -35,6 +35,8 @@
  * (easy to change)
  */
 
+#define	CONFIG_SYS_TEXT_BASE	0xFFF00000
+
 /* these hardware addresses are pretty bogus, please change them to
    suit your needs */