DM9000: Remove barely used SROM array read.

The srom array in the board data is only being used in the device probe
routines. The probe also only uses the first 6 bytes of an array
we spend 512ms reading 128 bytes from. Change to reading the
MAC area directly to the MAC address structure.

As a side product, we rename the read_srom_word to dm9000_read_eeprom
to bring it into line with the rest of the driver. No change is made
to the delay in this function, which will be dealt with in a later
patch.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>