sparc64: Get rid of real_setup_per_cpu_areas().

Now that we defer the cpu_data() initializations to the end of per-cpu
setup, we can get rid of this local hack we had to setup the per-cpu
areas eary.

This is a necessary step in order to support HAVE_DYNAMIC_PER_CPU_AREA
since the per-cpu setup must run when page structs are available.

Signed-off-by: David S. Miller <davem@davemloft.net>