Currently, bhyve PCI emulation uses vm_lapic_msi() to raise an MSI in
the guest. The arm64 port has a similar function, vm_raise_msi().
Add vm_raise_msi() on amd64 as well and have it simply call
vm_lapic_msi() so that bhyve can use a common, generically named
function.
For some reason the arm64 VM_RAISE_MSI ioctl takes a PCI device
identifier, but it is unused. Simply remove those parameters from the
arm64 prototype for now.