atheros: add support for linux kernel v3.8

This builds and boots.

Because of the function pointer indirection (e.g. mtd_info's read
function pointer is assigned to spiflash_read), it is difficult for me
to understand where the calls are coming from (could be anywhere,
conditionally pointing at spiflash versions), so I punted and used the
renamed function pointers (_erase, _read, _write).  If someone knows
better what to do, please fix.

Cleaned up other sundry kernel tracking issues like get_phy_id and
__devinit,etc.

[juhosg: don't switch to that yet]

Signed-off-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35727 3c298f89-4303-0410-b956-a3cf2f4a3e73