f2fs: support large folio for immutable non-compressed case

f2fs: support large folio for immutable non-compressed case

This patch enables large folio for limited case where we can get the high-order
memory allocation. It supports the encrypted and fsverity files, which are
essential for Android environment.

How to test:
- dd if=/dev/zero of=/mnt/test/test bs=1G count=4
- f2fs_io setflags immutable /mnt/test/test
- echo 3 > /proc/sys/vm/drop_caches
 : to reload inode with large folio
- f2fs_io read 32 0 1024 mmap 0 0 /mnt/test/test

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>