RISC-V: paravirt: pvqspinlock: KVM: Implement kvm_sbi_ext_pvlock_kick_cpu()

We only need to call the kvm_vcpu_kick() and bring target_vcpu
from the halt state. No irq raised, no other request, just a pure
vcpu_kick.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>