PCI: hv: Refactor hv_irq_unmask() to use cpumask_to_vpset()
Remove the duplicate implementation of cpumask_to_vpset() and use the
shared implementation. Export hv_max_vp_index, which is required by
cpumask_to_vpset().
Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>