scsi: docs: convert arcmsr_spec.txt to ReST

This file had its own peculiar style, not following any other
files inside the Kernel (as far as I saw).

Had to do a number of changes here, starting by removing the two
leading asterisks from each line, adding table and literal
block markups and changing whitespace and blank lines.

The end result is that (IMHO), it is now a lot easier to read
it as a text file, while producing a good html output.

Link: https://lore.kernel.org/r/6f8e4da4ea643adbe048f55504a59427c5e50c97.1583136624.git.mchehab+huawei@kernel.orgSigned-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Documentation/scsi/index.rst

@@ -13,6 +13,7 @@ Linux SCSI Subsystem
    aha152x
    aic79xx
    aic7xxx
+   arcmsr_spec
    bfa
    bnx2fc
    BusLogic

drivers/scsi/arcmsr/arcmsr_attr.c

@@ -41,7 +41,7 @@
 ** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *******************************************************************************
 ** For history of changes, see Documentation/scsi/ChangeLog.arcmsr
-**     Firmware Specification, see Documentation/scsi/arcmsr_spec.txt
+**     Firmware Specification, see Documentation/scsi/arcmsr_spec.rst
 *******************************************************************************
 */
 #include <linux/module.h>

drivers/scsi/arcmsr/arcmsr_hba.c

@@ -41,7 +41,7 @@
 ** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *******************************************************************************
 ** For history of changes, see Documentation/scsi/ChangeLog.arcmsr
-**     Firmware Specification, see Documentation/scsi/arcmsr_spec.txt
+**     Firmware Specification, see Documentation/scsi/arcmsr_spec.rst
 *******************************************************************************
 */
 #include <linux/module.h>