scsi: mpt3sas: Fix adapter replyPostRegisterIndex declaration

The replyPostRegisterIndex array of struct MPT3SAS_ADAPTER stores iomem
resource addresses. Fix its declaration to annotate it with __iomem to
avoid sparse warnings for writel() calls using the stored addresses.

Link: https://lore.kernel.org/r/20220307234854.148145-6-damien.lemoal@opensource.wdc.com


Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>