From: Paul Mackerras <paulus@samba.org>

Matt Porter's recent changes broke the compile for non-4xx ppc32 systems,
unfortunately.  I get an error that mfdcr is not defined in
include/asm-ppc/ocp.h when compiling for powermac (reasonable, since the
mfdcr instruction only exists on 4xx processors).  The patch below fixes
it.