PCI: rcar: Fix calculating mask for PCIEPAMR register

The mask value was calculated incorrectly for PCIEPAMR register if the
size was less than 128 bytes. Fix this issue by adding a check on size.

Link: https://lore.kernel.org/r/1588854799-13710-4-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

drivers/pci/controller/pcie-rcar.c

@@ -76,7 +76,10 @@ void rcar_pcie_set_outbound(struct rcar_pcie *pcie, int win,
 	 * keeps things pretty simple.
 	 */
 	size = resource_size(res);
-	mask = (roundup_pow_of_two(size) / SZ_128) - 1;
+	if (size > 128)
+		mask = (roundup_pow_of_two(size) / SZ_128) - 1;
+	else
+		mask = 0x0;
 	rcar_pci_write_reg(pcie, mask << 7, PCIEPAMR(win));
 
 	if (res->flags & IORESOURCE_IO)