pci: Add PCI_DEVICE_SUB() macro

This was added as part of commit 3d567e0e ('tg3: Set 10_100_ONLY
flag for additional 10/100 Mbps devices') upstream and is needed by
the following patch to ahci.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

include/linux/pci.h

@@ -589,6 +589,20 @@ struct pci_driver {
 	.vendor = (vend), .device = (dev), \
 	.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
 
+/**
+ * PCI_DEVICE_SUB - macro used to describe a specific pci device with subsystem
+ * @vend: the 16 bit PCI Vendor ID
+ * @dev: the 16 bit PCI Device ID
+ * @subvend: the 16 bit PCI Subvendor ID
+ * @subdev: the 16 bit PCI Subdevice ID
+ *
+ * This macro is used to create a struct pci_device_id that matches a
+ * specific device with subsystem information.
+ */
+#define PCI_DEVICE_SUB(vend, dev, subvend, subdev) \
+	.vendor = (vend), .device = (dev), \
+	.subvendor = (subvend), .subdevice = (subdev)
+
 /**
  * PCI_DEVICE_CLASS - macro used to describe a specific pci device class
  * @dev_class: the class, subclass, prog-if triple for this device