Restructure code to make it easier to maintain.

rhine_hw_init: resets chip, reloads eeprom
rhine_chip_reset: chip reset + what used to be wait_for_reset
rhine_reload_eeprom: reload eeprom, re-enable MMIO, disable EEPROM-controlled
	WOL

Note: Chip reset clears a bunch of registers that should be reloaded
from EEPROM (which turns off MMIO). Deal with that later.
Signed-off-by: Roger Luethi <rl@hellgate.ch>