When a device cannot handle the smallest previously limited transfer
size (64 blocks) without stalling, limit the device to the amount of
packets that fit in a platform native page.

The lowest possible limit is PAGE_CACHE_SIZE, so if the device is ever
used on a platform that has larger than 8K pages, you lose unless you
can convince the device firmware folks to fix the issue.

Cc: Mathew Dharm <mdharm-scsi@one-eyed-alien.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NDoug Maxey <dwm@austin.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>