xtensa-lx
* Remove mutex, InterruptNumber, bare_metal and spin * Changelog
xtensa-lx-rt
* Add the `xtensa-lx` package * Add the `xtensa-lx-rt` and `xtensa-lx-rt-proc-macros` packages * Exclude new packages from workspace, add to `xtask::Package` * rustfmt * clippy