DragonFlyBSD

This patch is to fix bugs associated with TRIM.

If trim is on as a option, display that when typing "mount".

Change post-trim ffs_blkfree_cg() to use taskqueue_swi_mp and get mp token when modifying freemap.

Make sure TRIM works with softdep. Stash a copy of that vnode's mount point in the ufs inode so that if we are using softdep, we can get access to the mount point through the faked up inode (created in freeblocks). The original mount point path (ip->i_devvp->v_mount->mnt_flag) doesn't have the mount point options.

Tim