Use dv_xname instead of if_xname to establish our interrupt.  The latter is still unset when at this point, and some MD variants of pci_intr_establish(9) make a copy of the string instead of storing a pointer.
Use dv_xname instead of if_xname to establish our interrupt.  The latter is
still unset when at this point, and some MD variants of pci_intr_establish(9)
make a copy of the string instead of storing a pointer.

Makes vmstat -i properly print the device name on sparc64.

ok mikeb@, deraadt@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars