ASoC: Updates for v5.4

Quite a big update this time around, particularly in the core
where we've had a lot of cleanups from Morimoto-san - there's
not much functional change but quite a bit of modernization
going on.  We've also seen a lot of driver work, a lot of it
cleanups but also some particular drivers.

 - Lots and lots of cleanups from Morimoto-san and Yue Haibing.
 - Lots of cleanups and enhancements to the Freescale, sunxi dnd
   Intel rivers.
 - Initial Sound Open Firmware suppot for i.MX8.
 - Removal of w90x900 and nuc900 drivers as the platforms are
   being removed.
 - New support for Cirrus Logic CS47L15 and CS47L92, Freescale
   i.MX 7ULP and 8MQ, Meson G12A and NXP UDA1334