[SCSI] aic94xx: update BIOS image from user space.

 1. Create a file "update_bios" in sysfs to allow user to update bios
    from user space.

 2. The BIOS image file can be downloaded from web site

"http://www.adaptec.com/en-US/downloads/bios_fw/bios_fw_ver?productId=SAS-48300&dn=Adaptec+Serial+Attached+SCSI+48300

"
    and copy the BIOS image into /lib/firmware folder.

 3. The aic994xx will accept "update bios_file" and "verify bios_file"
    commands to perform update and verify BIOS image .

    For example:

     Type "echo "update asc483c01.ufi" > /sys/devices/.../update_bios"
          to update BIOS image from /lib/firmware/as483c01.ufi file into
          HBA's flash memory.

     Type "echo "verify asc483c01.ufi" > /sys/devices/.../update_bios"
          to verify BIOS image between /lib/firmware/asc48c01.ufi file
and
          HBA's flash memory.

 4. Type "cat  /sys/devices/.../update_bios" to view the status or
result
    of updating BIOS.

Signed-off-by: Gilbert Wu <gilbert_wu@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>