fs/dax: remove FS_DAX_LIMITED config option

fs/dax: remove FS_DAX_LIMITED config option

The dcssblk driver was the last user of FS_DAX_LIMITED.  That was marked
broken by 653d7825c149 ("dcssblk: mark DAX broken, remove FS_DAX_LIMITED
support") to allow removal of PFN_SPECIAL.  However the FS_DAX_LIMITED
config option itself was not removed, so do that now.

Link: https://lkml.kernel.org/r/b47bf164b4a1013d736fa1a3d501bc8b8e71311f.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Björn Töpel <bjorn@rivosinc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>