move linux code into its subdirectory and move code that is shared between os implementations into root
These changes are to allow code sharing between linux and zephyr implementation.
- Moving linux code into a subdirectory
- move EddieEndpoint and EddieResource to root directory because both zephyr and linux code will share the same header files but with different implementations
see commit messages for more details
Signed-off-by: Francesco Pham francesco.pham@huawei.com