cpuat91: convert to new at91 soc architecture

convert the board to the new soc architecture
update default config
i2c upgrade taken from eb_cpux9k2.h & board/BuS/eb_cpux9k2/cpux9k2.c

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>
diff --git a/Makefile b/Makefile
index 4f1cb1b..f9e0eb9 100644
--- a/Makefile
+++ b/Makefile
@@ -1883,7 +1883,7 @@
 CPUAT91_config	:	unconfig
 	@mkdir -p $(obj)include
 	@echo "#define CONFIG_$(@:_config=) 1"	>$(obj)include/config.h
-	@$(MKCONFIG) -n $@ -a cpuat91 arm arm920t cpuat91 eukrea at91rm9200
+	@$(MKCONFIG) -n $@ -a cpuat91 arm arm920t cpuat91 eukrea at91
 
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 ## ARM926EJ-S Systems