[SCSI] aacraid: add new driver features flags

Feature enhancement, adding a 'flags' entry that will reside in the
host controller's tree, with a newline separated list of arbitrary
ascii named features that indicate whether the combination of driver
and controller has support for said feature. Breaking from the
one-line output typical of sysfs entries, newline was added to tailor
for grep, or simple gets line by line string match within an
application. I added one for a compiler time check for existence of
debug print output, one for an optional manifest defined enhanced
status reporting in the logs, and one for runtime reporting whether
the controller and driver supports arrays larger than 2TB. Adaptec's
storage management software uses the last flag to determine whether to
make available the creation of arrays larger than 2TB, otherwise a
warning is posted.

Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>