powerpc/64s/exception: Move EXCEPTION_COMMON additions into callers

More cases of code insertion via macros that does not add a great
deal. All the additions have to be specified in the macro arguments,
so they can just as well go after the macro.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>