target/arm/kvm64: kvm64 cpus have timer registers

target/arm/kvm64: kvm64 cpus have timer registers

Add the missing GENERIC_TIMER feature to kvm64 cpus.

We don't currently use these registers when KVM is enabled, but it's
probably best we add the feature flag for consistency and potential
future use. There's also precedent, as we add the PMU feature flag to
KVM enabled guests, even though we don't use those registers either.

This change was originally posted as a hunk of a different, never
merged patch from Bijan Mottahedeh.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200120101023.16030-4-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>