[POWERPC] Compile fixes for arch/powerpc dcr code

The new dcr code does not currently compile when configured for native
DCR access on ARCH=powerpc.  This patch fixes the problems.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-ppc/ibm4xx.h b/include/asm-ppc/ibm4xx.h
index 499c146..7a64ede 100644
--- a/include/asm-ppc/ibm4xx.h
+++ b/include/asm-ppc/ibm4xx.h
@@ -15,6 +15,7 @@
 #define __ASM_IBM4XX_H__
 
 #include <asm/types.h>
+#include <asm/dcr.h>
 
 #ifdef CONFIG_40x