ath9k: merge another round of cleanups and stability fixes, refresh patches

package/mac80211/patches/300-pending_work.patch

...ge/mac80211/patches/510-ath9k_intr_mitigation_tweak.patch

package/mac80211/patches/512-ath9k_channelbw_debugfs.patch

package/mac80211/patches/521-ath9k_cur_txpower.patch

...80211/patches/524-ath9k_use_configured_antenna_gain.patch

package/mac80211/patches/530-ath9k_extra_leds.patch

package/mac80211/patches/553-ath9k_debugfs_diag.patch

.../555-ath9k-allow-to-disable-bands-via-platform-data.patch

package/mac80211/patches/605-rt2x00-pci-eeprom.patch