target/ppc: remove ppc_cpu_dump_statistics

target/ppc: remove ppc_cpu_dump_statistics

This function requires surce code modification to be useful, which means
it probably is not used often, and the move to using decodetree means
the statistics won't even be collected anymore.

Also removed setting dump_statistics in ppc_cpu_realize, since it was
only useful when in conjunction with ppc_cpu_dump_statistics.

Suggested-by: Richard Henderson<richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Message-Id: <20210526202104.127910-3-bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>