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/sbc8641d.h b/include/configs/sbc8641d.h
index 32c8c18..bc9a56a 100644
--- a/include/configs/sbc8641d.h
+++ b/include/configs/sbc8641d.h
@@ -43,6 +43,8 @@
 #define CONFIG_MP		1	/* support multiple processors */
 #define CONFIG_LINUX_RESET_VEC  0x100   /* Reset vector used by Linux */
 
+#define	CONFIG_SYS_TEXT_BASE	0xfff00000
+
 #ifdef RUN_DIAG
 #define CONFIG_SYS_DIAG_ADDR        0xff800000
 #endif