brcm80211: simplify makefiles

This came up during my backporting work but it seems
perfectly appropriate for the kernel as well.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmsmac/Makefile

@@ -21,7 +21,7 @@ ccflags-y := \
 	-Idrivers/net/wireless/brcm80211/brcmsmac/phy \
 	-Idrivers/net/wireless/brcm80211/include
 
-BRCMSMAC_OFILES := \
+brcmsmac-y := \
 	mac80211_if.o \
 	ucode_loader.o \
 	ampdu.o \
@@ -43,11 +43,6 @@ BRCMSMAC_OFILES := \
 	brcms_trace_events.o \
 	debug.o
 
-ifdef CONFIG_BCMA_DRIVER_GPIO
-BRCMSMAC_OFILES += led.o
-endif
+brcmsmac-$(CONFIG_BCMA_DRIVER_GPIO) += led.o
 
-MODULEPFX := brcmsmac
-
-obj-$(CONFIG_BRCMSMAC)	+= $(MODULEPFX).o
-$(MODULEPFX)-objs	= $(BRCMSMAC_OFILES)
+obj-$(CONFIG_BRCMSMAC)	+= brcmsmac.o