bcm47xx: make it possible to build bcm47xx without ssb.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/arch/mips/bcm47xx/time.c b/arch/mips/bcm47xx/time.c
index 50aea2e..03dfc65 100644
--- a/arch/mips/bcm47xx/time.c
+++ b/arch/mips/bcm47xx/time.c
@@ -40,9 +40,11 @@
 	write_c0_compare(0xffff);
 
 	switch (bcm47xx_bus_type) {
+#ifdef CONFIG_BCM47XX_SSB
 	case BCM47XX_BUS_TYPE_SSB:
 		hz = ssb_cpu_clock(&bcm47xx_bus.ssb.mipscore) / 2;
 		break;
+#endif
 	}
 
 	if (!hz)