This patch series transitions the documentation
for remoteproc from the staging directory to the
mainline kernel. It introduces both kernel and
user-space APIs, enhancing the overall documentation
quality. Additionally, an index has been added to
ensure compatibility with the readthedocs.io
formatting requirements.

V3:
Seperated out the patches further to make the intention
clear for each patch.

V2:
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410161444.jOKMsoGS-lkp@intel.com/