* Remove duplicate config.txt copy statement
* Use static cmdline.txt file
Instead of dynamically creating cmdline.txt use a static version of it.
This aligns with other boot loader/firmware configuration files and makes
it easier to customize the file per board.
* Rename Intel NUC machine to Generic x86-64
The Intel NUC machine has evolved and supports various x86-64 machines
today. Rename the board.
Note that this does not address the migration issue. This will be
handled separately.
* Update Scripts/Documentation
