ath9k: add some cleanups and minor fixes

package/kernel/mac80211/patches/300-pending_work.patch

.../patches/402-ath9k-fix-invalid-mac-address-handling.patch

...ernel/mac80211/patches/410-ath9k_allow_adhoc_and_ap.patch

.../kernel/mac80211/patches/501-ath9k-eeprom_endianess.patch

package/kernel/mac80211/patches/502-ath9k_ahb_init.patch

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

package/kernel/mac80211/patches/511-ath9k_reduce_rxbuf.patch

...kernel/mac80211/patches/512-ath9k_channelbw_debugfs.patch

package/kernel/mac80211/patches/513-ath9k_add_pci_ids.patch

package/kernel/mac80211/patches/521-ath9k_cur_txpower.patch

...ac80211/patches/522-ath9k_per_chain_signal_strength.patch

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

package/kernel/mac80211/patches/530-ath9k_extra_leds.patch

...kernel/mac80211/patches/541-ath9k_rx_dma_stop_check.patch

package/kernel/mac80211/patches/542-ath9k_debugfs_diag.patch

.../543-ath9k-allow-to-disable-bands-via-platform-data.patch