[PATCH] powerpc: enable PPC_PTRACE_[GS]ETREGS on ppc32

I have tested PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS on umview.

I do not understand why historically these tags has been defined as
PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS instead of simply
PTRACE_[GS]ETREGS. The other "originality" is that the address must be
put into the "addr" field instead of the "data" field as stated in the
manual.

Signed-off-by: renzo davoli <renzo@cs.unibo.it>
Signed-off-by: Paul Mackerras <paulus@samba.org>