Avoid the sparse warning "warning: cast removes address space '__iomem' of
expression" by declaring the qp pointer as "u32 __iomem *".  Accordingly,
change the accesses to the qp array to use readl().

Link: https://lore.kernel.org/r/20220220031810.738362-3-damien.lemoal@opensource.wdc.comReviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>