Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

eliminate gainFCorrection; just have ar5212GetGainFCorrection return
the calculated value as it's only used in one place

On some platforms touching the bb registers when the phy is powered
down will cause a fault. Check the phy power state before possibly
reading from the bb, this can happen as ar5212Reset intentionally
calls ar5212GetRfgain before bringing the bb out of reset (but we
do it here and not in the caller to guard against other possible uses).

add FreeBSD property

import ath hal

Replace most compile-time support options with linker sets for
chip and RF backend support:
o add OS_DATA_SET and OS_SET_DECLARE os requirements for setting
up linker sets
o add AH_CHIP macro for registering chip support (e.g. 5210)
o add AH_RF macro for registering RF support (e.g. 2413); note
this isn't required for single chip solutions where there's no
ambiguity (e.g. 5416/9160+2133) but for 5212 class parts it's
required because of the multi-chip solutions
o remove all uses of AH_SUPPORT_AR5210, AH_SUPPORT_AR5211, AH_SUPPORT_5212,
and AH_SUPPORT_AR9160; still need AH_SUPPORT_AR5416 to enable the 11n
descriptor formats and 5312 support is presently broken
o remove all uses of AH_SUPPORT_2133, AH_SUPPORT_2413, AH_SUPPORT_5111,
AH_SUPPORT_5112, AH_SUPPORT_2417, AH_SUPPORT_2425, and AH_SUPPORT_5413;
5312-related support still requires fixup

Remaining issues:
o fixup SoC attach
o ath_hal_attach uses a hack to probe w/o access to the vendorid
o fallback handling of parts w/o a macrev needs to be restored

Update to later code from my repository:
o many bug fixes
o add new periodic calibration api
o break up 5416 periodic calibration code in preparation for 928x
o move get noise floor to rf backends
o 5416-specific ani (still disabled)
o modularize 5210 eeprom format a la other eeprom formats
o start cleaning up regdomain code
o prepare for proper 1/2 and 1/4 width channel support
o bring back 900MHz card support
o clean up 5212 rf version handling
o add 1/2 and 1/4 width channel support for 5212 parts
o split 5212 rfgain handling out
o improve ani debugging
o add AH_USE_INIPDGAIN compile option
o purge a bunch of dead 5212 state
o add 1/2 and 1/4 rate modes
o remove HAL_CAP_CHAN_HALFRATE and HAL_CAP_CHAN_QUARTERRATE; the
same info can now be deduced from the set of supported modes