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/OXC.h b/include/configs/OXC.h
index 7f4babe..76d8b04 100644
--- a/include/configs/OXC.h
+++ b/include/configs/OXC.h
@@ -39,6 +39,8 @@
 #define CONFIG_MPC8240		1
 #define CONFIG_OXC		1
 
+#define	CONFIG_SYS_TEXT_BASE	0xFFF00000
+
 #define CONFIG_BOARD_EARLY_INIT_F 1	/* Call board_early_init_f	*/
 
 #define CONFIG_IDENT_STRING     " [oxc] "