This updates the minimal supported version of CMake to 3.16, which in turn enables us to use more CMake features and have a cleaner build system.
This is the version that provides most new features and also the one we use in our latest docker image for CI.
The following files have been ported:
* esp_rom_crc.h
* esp_rom_sys.h
* esp_rom_efuse.h (mostly no-ops)
* esp_rom_md5.h
Integrated Linux-based rom implementation into log
and NVS component.
Added brief host tests for ROM to ensure basic
consistency on Linux.
Added ROM printf host unit tests.
Temporarily added reset reason for Linux in ROM.
