sd: Disable support for 256 byte/sector disks

sd: Disable support for 256 byte/sector disks

commit 74856fbf441929918c49ff262ace9835048e4e6a upstream.

256 bytes per sector support has been broken since 2.6.X,
and no-one stepped up to fix this.
So disable support for it.

Signed-off-by: Mark Hounschell <dmarkh@cfl.rr.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit fd6b72574fcdaee123768804d8f1ac28c2a5b3de)

Signed-off-by: Willy Tarreau <w@1wt.eu>