hpsa: adjust RAID-1, RAID-1ADM, and RAID-6 names

HP now uses RAID-6 rather than RAID-ADG (Advanced Data Guarding)
as the marketing name for our implementation of RAID-6.

The driver considers RAID-1 and RAID-1+0 to be the same level, and
considers RAID-1ADM and RAID-1+0ADM to be the same level.  Parenthesis
can be used to reflect the optional +0 portion of both those RAID levels.

Rename: RAID-ADG to RAID-6
	RAID-1(1+0) to RAID-1(+0)
	RAID-1(ADM) to RAID-1(+0)ADM

Also, add another const after the pointer type as suggested
by checkpatch.pl so the array is:
	static const char * const raid_label[]

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>