target-arm: kvm64 - introduce kvm_arm_init_debug()

target-arm: kvm64 - introduce kvm_arm_init_debug()

As we haven't always had guest debug support we need to probe for it.
Additionally we don't do this in the start-up capability code so we
don't fall over on old kernels.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1449599553-24713-2-git-send-email-alex.bennee@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>