MFC r240514:

MFC r240514:

isci(4): Fix SCSI/ATA translation for SCSI_WRITE_BUFFER w/ mode==0x7
(download microcode with offsets, save, and activate).

SATI translation layer was incorrectly using allocation length instead
of blocks, and was constructing the ATA command incorrectly.

Also change #define to specify that the 512 block size here is
specific for DOWNLOAD_MICROCODE, and does not relate to the device's
logical block size.

Approved by:   re (kib)

git-svn-id: svn://svn.freebsd.org/base/releng/9.1@240614 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f