ssb: fix PCI(e) driver regression causing oops on PCI cards

We were incorrectly executing PCIe specific workarounds on PCI cards.
This resulted in:
Machine check in kernel mode.
Caused by (from SRR1=149030): Transfer error ack signal
Oops: Machine check, sig: 7 [#1]
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/driver_pcicore.c

@@ -539,10 +539,12 @@ void ssb_pcicore_init(struct ssb_pcicore *pc)
 	if (!pc->hostmode)
 		ssb_pcicore_init_clientmode(pc);
 
-	/* Additional always once-executed workarounds */
-	ssb_pcicore_serdes_workaround(pc);
-	/* TODO: ASPM */
-	/* TODO: Clock Request Update */
+	/* Additional PCIe always once-executed workarounds */
+	if (dev->id.coreid == SSB_DEV_PCIE) {
+		ssb_pcicore_serdes_workaround(pc);
+		/* TODO: ASPM */
+		/* TODO: Clock Request Update */
+	}
 }
 
 static u32 ssb_pcie_read(struct ssb_pcicore *pc, u32 address)