scsi: mpt3sas: Fix spelling mistake in Kconfig "compatiblity" -> "compatibility"

There is a spelling mistake in the Kconfig help text. Fix it.

Link: https://lore.kernel.org/r/20201217172019.57768-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Colin Ian King

drivers/scsi/mpt3sas/Kconfig

@@ -79,5 +79,5 @@ config SCSI_MPT2SAS
 	select SCSI_MPT3SAS
 	depends on PCI && SCSI
 	help
-	Dummy config option for backwards compatiblity: configure the MPT3SAS
+	Dummy config option for backwards compatibility: configure the MPT3SAS
 	driver instead.