[POWERPC] Uninline common ptrace bits

This folds back the ptrace-common.h bits back into ptrace.c and removes
that file. The FSL SPE bits from ptrace-ppc32.h are folded back in as
well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>