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/A3000.h b/include/configs/A3000.h
index 0532a75..ffc58af 100644
--- a/include/configs/A3000.h
+++ b/include/configs/A3000.h
@@ -45,6 +45,7 @@
 #define CONFIG_MPC8245		1
 #define CONFIG_A3000		1
 
+#define	CONFIG_SYS_TEXT_BASE	0xFFF00000
 
 #define CONFIG_CONS_INDEX	1
 #define CONFIG_BAUDRATE		9600