This commit adds the source files for the FreeRTOS Kernel V10.5.1 in
preparation for upgrading ESP-IDF FreeRTOS Kernel version (files copied from
https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/V10.5.1)
The following modifications were made to the files when copying
- Added "SPDX-FileCopyrightText" and "SPDX-FileContributor" tags to all files
to pass ESP-IDF pre-commit checks.
- Left out some files unnecessary to ESP-IDF (e.g., URLs, "History.txt", and
"portable" folder).
