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/NX823.h b/include/configs/NX823.h
index 5054d5e..70c6bb5 100644
--- a/include/configs/NX823.h
+++ b/include/configs/NX823.h
@@ -39,6 +39,8 @@
 #define CONFIG_MPC823		1	/* This is a MPC823 CPU	    */
 #define CONFIG_NX823		1	/* ...on a NEXUS 823  module	*/
 
+#define	CONFIG_SYS_TEXT_BASE	0x40000000
+
 /*#define  CONFIG_VIDEO		1 */
 
 #define CONFIG_8xx_GCLK_FREQ	MPC8XX_SPEED