libata: backport ATA_FLAG_NO_SRST and ATA_FLAG_ASSUME_ATA

libata: backport ATA_FLAG_NO_SRST and ATA_FLAG_ASSUME_ATA

Differs from mainline, but the functionality is already there.

Backport ATA_FLAG_NO_SRST and ATA_FLAG_ASSUME_ATA.  These are
originally link flags (ATA_LFLAG_*) but link abstraction doesn't exist
on 2.6.23, so make it port flags.

This is for the following workaround for ASUS P5W DH Deluxe.

These new flags don't introduce any behavior change unless set and
nobody sets them yet.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>