ppc4xx: cleanup CPCI4052 board

- remove some obsolete code
- switch to generic board

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu>
diff --git a/board/esd/cpci405/Makefile b/board/esd/cpci405/Makefile
index b140571..7490b78 100644
--- a/board/esd/cpci405/Makefile
+++ b/board/esd/cpci405/Makefile
@@ -5,5 +5,5 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y	= cpci405.o flash.o ../common/misc.o ../common/auto_update.o
+obj-y	= cpci405.o flash.o ../common/misc.o
 obj-y	+= ../common/cmd_loadpci.o