[SCSI] megaraid_sas: add new controllers (0x78 0x79)

Add the new controllers (0x78 0x79) support to the driver.  Those
controllers are LSI's next generation (gen2) SAS controllers.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: parenthesise a macro]
Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>