fdtbus_clock_count
sc->sc_nparent = fdtbus_clock_count(phandle, "clocks");
const u_int nclocks = fdtbus_clock_count(phandle, "assigned-clocks");
const u_int nparents = fdtbus_clock_count(phandle, "assigned-clock-parents");
u_int fdtbus_clock_count(int, const char *);