(split) Add an automatic resize support to the GEOM_PART class.

When parent provider has been resized, the scheme specific G_PART_RESIZE
method does an update of scheme's metadata. But all changes are not saved
to disk, until `gpart commit` will be called.

Discussed with:	trasz
MFC after:	1 month
(split) Fix rf registers for RT3070.
(split) Fix lower bits of RF_R3 for RT3370 and newer.  This change doesn't affect
older chipsets.
(split) Since the DAC issue has been fixed in RT3070(F), the voltage raising fix
is no longer needed.
(split) Correct tx mixer gain value for RT3070 and RT3071.

Correctly value in EEPROM/EFUSE is one or more for RT3070 and
two or more for other RT3071 chips.
(split) Fix the RT2860_TX_SW_CFG2 init value on older revisions of RT3070 chip.
(split) Merge branch 'CURRENT' (commit '76ca16ff')