erofs: introduce nolargefolio mount option

This patch introduces a new mount option 'nolargefolio' for EROFS.
When this option is specified, large folio will be disabled by
default for all inodes, this option can be used for environments
where large folio resources are limited, it's necessary to only
let specified user to allocate large folios on demand.

Signed-off-by: Chao Yu <chao@kernel.org>