sound updates for 5.1 We had again a busy development cycle with many new drivers as well as lots of core improvements / cleanups. Let's go for highlights: ALSA core: - PCM locking scheme was refactored for reducing a global rwlock - PCM suspend is handled in the device type PM ops now; lots of explicit calls were reduced by this action - Cleanups about PCM buffer preallocation calls - Kill NULL device object in memory allocations - Lots of procfs API cleanups ASoC core: - Support for only powering up channels that are actively being used - Cleanups / fixes of topology API ASoC drivers: - MediaTek BTCVSD for a Bluetooth radio chip, which is the first such driver we've had upstream! - Quite a few improvements to simplify the generic card drivers, especially the merge of the SCU cards into the main generic drivers - Lots of fixes for probing on Intel systems to follow more standard styles - A big refresh and cleanup of the Samsung drivers - New drivers: Asahi Kasei Microdevices AK4497, Cirrus Logic CS4341 and CS35L26, Google ChromeOS embedded controllers, Ingenic JZ4725B, MediaTek BTCVSD, MT8183 and MT6358, NXP MICFIL, Rockchip RK3328, Spreadtrum DMA controllers, Qualcomm WCD9335, Xilinx S/PDIF and PCM formatters ALSA drivers: - Improvements of Tegra HD-audio controller driver for supporting new chips - HD-audio codec quirks for ALC294 S4 resume, ASUS laptop, Chrome headset button support and Dell workstations - Improved DSD support on USB-audio - Quirk for MOTU MicroBook II USB-audio - Support for Fireface UCX support and Solid State Logic Duende Classic/Mini