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/RPXsuper.h b/include/configs/RPXsuper.h
index ec891e4..f4f90f2 100644
--- a/include/configs/RPXsuper.h
+++ b/include/configs/RPXsuper.h
@@ -1,6 +1,7 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define	CONFIG_SYS_TEXT_BASE	0x80F00000
 
 /*****************************************************************************
  *