PCI: Add two more values for PCIe Max_Read_Request_Size

This patch adds missing values for the max read request size.
E.g. network driver r8169 uses a value of 4K.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/pci_regs.h

@@ -506,6 +506,8 @@
 #define  PCI_EXP_DEVCTL_READRQ_256B  0x1000 /* 256 Bytes */
 #define  PCI_EXP_DEVCTL_READRQ_512B  0x2000 /* 512 Bytes */
 #define  PCI_EXP_DEVCTL_READRQ_1024B 0x3000 /* 1024 Bytes */
+#define  PCI_EXP_DEVCTL_READRQ_2048B 0x4000 /* 2048 Bytes */
+#define  PCI_EXP_DEVCTL_READRQ_4096B 0x5000 /* 4096 Bytes */
 #define  PCI_EXP_DEVCTL_BCR_FLR 0x8000  /* Bridge Configuration Retry / FLR */
 #define PCI_EXP_DEVSTA		10	/* Device Status */
 #define  PCI_EXP_DEVSTA_CED	0x0001	/* Correctable Error Detected */