Flags to use below are either passed in or the current band flags are taken (or 0 if bands not initialised yet)
- if core is up, reset DMA/PIO engine
reset the core on the backplane using the flags ORed with PHY Clock Enable and PHY Reset
- wait for the PLL to turn on (150 microseconds)
take PHY out of reset
- turn on analog if band PHY has been attached already
set MAC Control IHR Region Enabled bit
FIXME: needs more work for N PHY chips with power management unit (PHY rev >= 3, 4322 chip)