Various instances of the EMAC core have varying: 1) number of address
match slots, 2) width of the registers for handling address match slots,
3) number of registers for handling address match slots and 4) base
offset for those registers.

As the driver stands today, it assumes that all EMACs have 4 IAHT and
GAHT 32-bit registers, starting at offset 0x30 from the register base,
with only 16-bits of each used for a total of 64 match slots.

The 405EX(r) and 460EX now use the EMAC4SYNC core rather than the EMAC4
core. This core has 8 IAHT and GAHT registers, starting at offset 0x80
from the register base, with ALL 32-bits of each used for a total of
256 match slots.

This adds a new compatible device tree entry "emac4sync" and a new,
related feature flag "EMAC_FTR_EMAC4SYNC" along with a series of macros
and inlines which supply the appropriate parameterized value based on
the presence or absence of the EMAC4SYNC feature.

The code has further been reworked where appropriate to use those macros
and inlines.

In addition, the register size passed to ioremap is now taken from the
device tree:

	c4 for EMAC4SYNC cores
	74 for EMAC4 cores
	70 for EMAC cores

rather than sizeof (emac_regs).

Finally, the device trees have been updated with the appropriate compatible
entries and resource sizes.

This has been tested on an AMCC Haleakala board such that: 1) inbound
ICMP requests to 'haleakala.local' via MDNS from both Mac OS X 10.4.11
and Ubuntu 8.04 systems as well as 2) outbound ICMP requests from
'haleakala.local' to those same systems in the '.local' domain via MDNS
now work.
Signed-off-by: Grant Erickson <gerickson@nuovations.com>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>