[POWERPC] Remove remaining iSeries debugger cruft

None of this seems to be necessary, so let's see if can remove it and not
break anything. Booted on iSeries & pSeries here.

NB. we don't remove the hvReleaseData, we just move it down so that the file
reads more clearly.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>