convert drivers/base/power/Makefile to ccflags

This patch converts drivers/base/power/Makefile to use ccflags instead
of EXTRA_CFLAGS.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

drivers/base/power/Makefile

@@ -2,9 +2,5 @@ obj-$(CONFIG_PM)	+= sysfs.o
 obj-$(CONFIG_PM_SLEEP)	+= main.o
 obj-$(CONFIG_PM_TRACE)	+= trace.o
 
-ifeq ($(CONFIG_DEBUG_DRIVER),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
-ifeq ($(CONFIG_PM_VERBOSE),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
+ccflags-$(CONFIG_PM_VERBOSE)   += -DDEBUG