sparc64: Clean up CPU chip type probing code.

sparc64: Clean up CPU chip type probing code.

Three main things:

1) Make prober an arch initcall instead of using hard-coded invocation
   from paging_init()

2) Shrink table size, the fpu ident stuff was never used.

3) Use named struct initialized in table.

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