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/P3G4.h b/include/configs/P3G4.h
index 6aa214a..5f3c414 100644
--- a/include/configs/P3G4.h
+++ b/include/configs/P3G4.h
@@ -42,6 +42,8 @@
 #define CONFIG_P3G4		1	/* this is a P3G4  board	*/
 #define CONFIG_SYS_GT_6426x        GT_64260 /* with a 64260 system controller */
 
+#define	CONFIG_SYS_TEXT_BASE	0xfff00000
+
 #define CONFIG_BAUDRATE		115200	/* console baudrate = 115200	*/
 
 #undef	CONFIG_ECC			/* enable ECC support */