build: check for SEEK_HOLE and SEEK_DATA support

build: check for SEEK_HOLE and SEEK_DATA support

SEEK_HOLE and SEEK_DATA will be used in the implementation of
FSCTL_QUERY_ALLOCATED_RANGES support.

"SEEK_DATA and SEEK_HOLE are nonstandard extensions also present
 in Solaris, FreeBSD, and DragonFly BSD; they are proposed for
 inclusion in the next POSIX revision (Issue 8)."

With Linux they are supported on:
-  Btrfs (since Linux 3.1)
-  OCFS (since Linux 3.2)
-  XFS (since Linux 3.5)
-  ext4 (since Linux 3.8)
-  tmpfs (since Linux 3.8)

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>