b43: Don't compile N-PHY code when N-PHY is disabled

There's no need to compile the N-PHY support code, when the
N-PHY support is disabled in Kconfig.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/Makefile b/drivers/net/wireless/b43/Makefile
index ac1329d..ae11fe4 100644
--- a/drivers/net/wireless/b43/Makefile
+++ b/drivers/net/wireless/b43/Makefile
@@ -1,8 +1,8 @@
 b43-y				+= main.o
 b43-y				+= tables.o
-b43-y				+= tables_nphy.o
+b43-$(CONFIG_B43_NPHY)		+= tables_nphy.o
 b43-y				+= phy.o
-b43-y				+= nphy.o
+b43-$(CONFIG_B43_NPHY)		+= nphy.o
 b43-y				+= sysfs.o
 b43-y				+= xmit.o
 b43-y				+= lo.o