It looks like you somehow managed to not completely install 
one of the wraps.  I have a machine that we built with the
0327 full update and then has the 0425 and 0507 wraps applied
and it compiles kernels without a problem.

The addclock0link code moved from clock.c to port/portclock.c in the
0327 wrap to avoid doing the same thing in every architecture.  The
0425 wrap reinstalls port/portclock.c to fix a bug.  Looks lke you
still have a clock.c from before the 0327 version and also the
port/portclock.c