hwmon: change to new flag variable

Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

drivers/hwmon/Makefile

@@ -112,7 +112,5 @@ obj-$(CONFIG_SENSORS_W83L786NG)	+= w83l786ng.o
 obj-$(CONFIG_SENSORS_WM831X)	+= wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)	+= wm8350-hwmon.o
 
-ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
+ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG
-EXTRA_CFLAGS += -DDEBUG
-endif