Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Move this magic check to only occur if no eeprom data is given.

Tested on:

* AP99 (AR7241+AR9287)

Prepare for embedded use of the AR9285/AR9287.

Calibration/PCI data that's written to flash (rather than EEPROM attached
to the NIC) is typically already in host-endian. The existing checks
end up swapping 16 bit words incorrectly - the correct solution would be
to read the magic value and determine the EEPROM endianness from that.
(This is what Linux does.)

This doesn't completely enable embedded use of the AR9285/AR9287 -
notably, the EEPROM read methods need to be made generic and available
to all EEPROM drivers. I'll worry about that later.

Approved by: re (kib)

Fix a bad merge from a previous commit.

Add temp sense to the EEPROM variable list;
Export the temperature sense variables to ah_eeprom_9287.c

Fix the eeprom set API method to return HAL_STATUS.

The code assumed it could return HAL_OK, HAL_EINVAL and other
HAL_STATUS types; so it shouldn't be declared as returning HAL_BOOL.

This commit was brought to you by the Clang compiler.

Submitted by: Matthew Fleming <mdf356@gmail.com>

Import initial EEPROM code for Kite (AR9287).

I've tested this locally and it does indeed read and attach to an AR9287
EEPROM. But a lot more code needs to be ported over to the HAL before
the AR9287 is functional.

I'm importing this separate from the rest of the codebase (and unlinked from
the build for now) in case someone wishes to begin fiddling with porting
the rest of the code over from Linux ath9k.

Obtained from: Linux ath9k