Merge https://gitlab.denx.de/u-boot/custodians/u-boot-x86

Merge https://gitlab.denx.de/u-boot/custodians/u-boot-x86

- Various minor fixes for x86
- Switch to ACPI mode on Intel edison
- Support run-time configuration for NS16550 driver
- Update coreboot and slimbootloader serial drivers to use NS16550
run-time configuration
- ICH SPI driver fixes to hardware sequencing erase case
- Move ITSS from Apollo Lake to a more generic location
- Intel GPIO driver bug fixes
- Move to vs2017-win2016 platform build host for Azure pipelines