libata-eh.c: Introduce new ata port flag for controller which lockup on read log...

libata-eh.c: Introduce new ata port flag for controller which lockup on read log page

Some controller lockup on a ata_read_log_page.
Add new ata port flag ATA_FLAG_NO_LOG_PAGE which can used
to blacklist a controller.

If this flag is set, any attempt to read a log page returns an error
without actually issuing the command.

Signed-off-by: Andreas Werner <andreas.werner@men.de>
Signed-off-by: Tejun Heo <tj@kernel.org>