xfs: add a new xfs_sb_version_has_v3inode helper

Add a new wrapper to check if a file system supports the v3 inode format
with a larger dinode core.  Previously we used xfs_sb_version_hascrc for
that, which is technically correct but a little confusing to read.

Also move xfs_dinode_good_version next to xfs_sb_version_has_v3inode
so that we have one place that documents the superblock version to
inode version relationship.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>