ath9k_hw: add AR9580 support

ath9k_hw: add AR9580 support

Here are the AR9580 1.0 initvals checksums using the
Atheros initvals-tools [1]. This is useful for when
we udate the initvals again with other values. It ensures
that we match the same initvals used internally. The
tool is documented on the wiki [2].

$ ./initvals -f ar9580-1p0
0x00000000e912711f        ar9580_1p0_modes_fast_clock
0x000000004a488fc7        ar9580_1p0_radio_postamble
0x00000000f3888b02        ar9580_1p0_baseband_core
0x0000000003f783bb        ar9580_1p0_mac_postamble
0x0000000094be244a        ar9580_1p0_low_ob_db_tx_gain_table
0x0000000094be244a        ar9580_1p0_high_power_tx_gain_table
0x0000000090be244a        ar9580_1p0_lowest_ob_db_tx_gain_table
0x00000000ed9eaac6        ar9580_1p0_baseband_core_txfir_coeff_japan_2484
0x00000000c4d66d1b        ar9580_1p0_mac_core
0x00000000e8e9043a        ar9580_1p0_mixed_ob_db_tx_gain_table
0x000000003521a300        ar9580_1p0_wo_xlna_rx_gain_table
0x00000000301fc841        ar9580_1p0_soc_postamble
0x00000000a9a06b3a        ar9580_1p0_high_ob_db_tx_gain_table
0x00000000a15ccf1b        ar9580_1p0_soc_preamble
0x0000000029495000        ar9580_1p0_rx_gain_table
0x0000000037ac0ee8        ar9580_1p0_radio_core
0x00000000603a1b80        ar9580_1p0_baseband_postamble
0x000000003d8b4396        ar9580_1p0_pcie_phy_clkreq_enable_L1
0x00000000398b4396        ar9580_1p0_pcie_phy_clkreq_disable_L1
0x00000000397b4396        ar9580_1p0_pcie_phy_pll_on_clkreq

[1] git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/initvals-tool.git
[2] http://wireless.kernel.org/en/users/Drivers/ath9k_hw/initvals-tool

Cc: David Quan <dquan@qca.qualcomm.com>
Cc: Kathy Giori <kgiori@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>