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/cogent_mpc8xx.h b/include/configs/cogent_mpc8xx.h
index 329bc99..a23db1c 100644
--- a/include/configs/cogent_mpc8xx.h
+++ b/include/configs/cogent_mpc8xx.h
@@ -36,6 +36,8 @@
 #define CONFIG_MPC860		1	/* This is an MPC860 CPU	*/
 #define CONFIG_COGENT		1	/* using Cogent Modular Architecture */
 
+#define	CONFIG_SYS_TEXT_BASE	0xfff00000
+
 #define	CONFIG_MISC_INIT_F	1	/* Use misc_init_f()		*/
 #define	CONFIG_MISC_INIT_R		/* Use misc_init_r()		*/