scsi: mpt3sas: Swap I/O memory read value back to cpu endianness

Swap the I/O memory read value back to cpu endianness before storing it in
a data structures which are defined in the MPI headers where u8 components
are not defined in the endianness order.

In this area from day one mpt3sas driver is using le32_to_cpu() &
cpu_to_le32() APIs. But in commit cf6bf971
(mpt3sas: Bug fix for big endian systems) we have removed these APIs
before reading I/O memory which we should haven't done it. So
in this patch I am correcting it by adding these APIs back
before accessing I/O memory.

Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>