Second set of IIO new device support features and cleanup for the 4.20 cycle.

One merge commit in here to bring in the SPI_CS_WORD flag patches
that are also going via the SPI tree.

There are a few more fixes than normal for a pull targetting the
next merge window.  These are all long term issues and as we are late
in the cycle, they can wait.

New device support
* ad7606
  - Add support fo the ad7605-4 driver.  This driver is still in staging
    but is heading in the right direction to graduate, motivated partly
    by the requirement for this device support.
* ST VL53L0X ToF ranging sensor
  - New minimal driver. Interrupt support to follow.

New features

* SPI_CS_WORD optimization allows long transfers with the chip select
  toggled every 16bits.   There is a software fallback as well to let
  drivers not care about whether the hardware supports it.

* bh1750
  - Device tree support and bindings.
* ti-ads7950
  - Use the SPI_CS_WORD optmization to save lots of cpu cycles (assuming
    the hardware supports it)

Fixes and cleanups

* ad5064
  - Fix some long incorrect regulator error handling that preventing
    enabling the internal regulator.
* ad7606
  - The ad7606 doesn't actually have a 2.5V range and the values provided
    for scale have always been wrong.  Fix them.
  - Drop some wrong kernel-doc (things that don't exist)
  - Add missing kernel-doc
* at91-adc
  - Fixing missing ack of dataready on sysfs channel reads to avoid spurious
    interrupts.
  - Fix a wrong channel numbers in triggered_buffer_mode
* hmc5843
  - Fix incorrect part number in a comment.
* imx25-gcq
  - Fix a device_node leak in an error path.
* meson-saradc
  - Drop an unused and pointless define.
  - Use of_device_get_match_data instead of opencoding
  - Tidy up how meson_sar_adc_param is accessed.
  - Rework prior to adding some temperature sensor support.
-----BEGIN PGP SIGNATURE-----

iQJFBAABCAAvFiEEbilms4eEBlKRJoGxVIU0mcT0FogFAluyb14RHGppYzIzQGtl
cm5lbC5vcmcACgkQVIU0mcT0Fogh+Q/9EwIO/feLfyoC5RfgDzbvPUTFzvEEFpoh
HtlKRzKuQv03iWf0xb2XQPS0SBQSxldP0ugonBONENGR7mGf2vaF2cwrsPpe92JS
0jd64RND1mKmljsYb49ulm4wy2o5hAP2BH79sQku0ZwGlG8hhjgfdDo7Oz/PVwDL
Mra9WXRhVXTfE3V8rF5rDpRtD7pjDNQlXsVfMg5C5sloh+d3ebTuFnJxyWExMv7d
c1Hbh2JhJfDq0AmviTLdkQ8Sx8GpdFK8sYqkwcZUpMfrAutT/CL/zRDh4xOPe7+6
MRLfwd/w1zzsmaDWq+HiT70E2AVykKMhHbpJxLx/OPzibVsxOSRcm/y52M7kXqM2
nJFSu+qtoJO301nAycWzrrBaXGImuwtK9pt55Hi+3Ytc2xvJWA5QDnb1s6WV1xNY
I2jA9QFaWjRhLgZBlluDhd5gGNPQaKj9EvGrBTC8mUDc6ybItZvKiwSV5+eMQZYV
4jbFAgDWDafMDl/7NYhyir5T8u8mjaUlSS2/SQUYq7+GzjKXSdY51M8yro369Vj+
P9X93ObkK2IntfbMSh8RfIFJFR7BlKQcHjOf8t5GPLvDnFPlTppgcV+1ZBrTp4RF
V6UIOs5qZkXkR6/SIQl+e93i++LOmksVf1wMQ/WtfN7KhNdAYqaj2+W5SYWyYQMP
v/z+KNuoeXw=
=2Qke
-----END PGP SIGNATURE-----