rt2661_bbp_read
val = rt2661_bbp_read(sc, 0);
static uint8_t rt2661_bbp_read(struct rt2661_softc *, uint8_t);
bbp4 = rt2661_bbp_read(sc, 4);
bbp77 = rt2661_bbp_read(sc, 77);
bbp3 = rt2661_bbp_read(sc, 3);