powerpc/64: Replace -mcpu=e500mc64 by -mcpu=e5500

powerpc/64: Replace -mcpu=e500mc64 by -mcpu=e5500

commit 77e82fa1f9781a958a6ea4aed7aec41239a5a22f upstream.

E500MC64 is a processor pre-dating E5500 that has never been
commercialised. Use -mcpu=e5500 for E5500 core.

More details at https://gcc.gnu.org/PR108149

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fa71ed20d22c156225436374f0ab847daac893bc.1671475543.git.christophe.leroy@csgroup.eu
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>