This commit sorts the entries of variuos toctrees
alphabetically. Indentation was also fixed. The order
of some toctrees were not modified if the existing
order had some form of suggested reading order.
- Split SDMMC page into pages about SDMMC/SDSPI hosts and a page about
the protocol layer.
- Use autogenerated API reference instead of manually generated one.
- Add information about SDIO APIs.