rapidio/tsi721: use PCI define for Max_Read_Request_Size

Replace a magic number with a PCI #define symbol.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 8bcfecd..eeca70d 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -2430,7 +2430,7 @@
 	pcie_capability_clear_and_set_word(pdev, PCI_EXP_DEVCTL,
 		PCI_EXP_DEVCTL_READRQ | PCI_EXP_DEVCTL_RELAX_EN |
 		PCI_EXP_DEVCTL_NOSNOOP_EN,
-		0x2 << MAX_READ_REQUEST_SZ_SHIFT);
+		PCI_EXP_DEVCTL_READRQ_512B);
 
 	/* Adjust PCIe completion timeout. */
 	pcie_capability_clear_and_set_word(pdev, PCI_EXP_DEVCTL2, 0xf, 0x2);
diff --git a/drivers/rapidio/devices/tsi721.h b/drivers/rapidio/devices/tsi721.h
index a7b4268..9d25025 100644
--- a/drivers/rapidio/devices/tsi721.h
+++ b/drivers/rapidio/devices/tsi721.h
@@ -72,8 +72,6 @@
 #define TSI721_MSIXPBA_OFFSET	0x2a000
 #define TSI721_PCIECFG_EPCTL	0x400
 
-#define MAX_READ_REQUEST_SZ_SHIFT	12
-
 /*
  * Event Management Registers
  */