libxfs: fix incorrect porting to 6.7

Userspace libxfs is supposed to match the kernel libxfs except for the
preprocessor include directives.  Fix a few discrepancies that came up
for whatever reason.

To fix the build errors resulting from CONFIG_XFS_RT not being defined,
add it to libxfs.h and alter the Makefile to track xfs_rtbitmap.h.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>