[media] bt8xx: use pci_dev->subsystem_{vendor|device}

The driver reads PCI subsystem IDs from the PCI configuration registers while
they are already stored by the PCI subsystem in the 'subsystem_{vendor|device}'
fields of 'struct pci_dev'...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/bt8xx/bttv-cards.c

@@ -2892,13 +2892,10 @@ void __devinit bttv_idcard(struct bttv *btv)
 {
 	unsigned int gpiobits;
 	int i,type;
-	unsigned short tmp;
 
 	/* read PCI subsystem ID */
-	pci_read_config_word(btv->c.pci, PCI_SUBSYSTEM_ID, &tmp);
-	btv->cardid = tmp << 16;
-	pci_read_config_word(btv->c.pci, PCI_SUBSYSTEM_VENDOR_ID, &tmp);
-	btv->cardid |= tmp;
+	btv->cardid  = btv->c.pci->subsystem_device << 16;
+	btv->cardid |= btv->c.pci->subsystem_vendor;
 
 	if (0 != btv->cardid && 0xffffffff != btv->cardid) {
 		/* look for the card */