[media] drivers/staging/media/as102: using ccflags-y instead of EXTRA_FLAGS in Makefile

need using ccflags-y instead of EXTRA_CFLAGS
    can reference scripts/checkpatch.pl (1755..1766)
  when make EXTRA_CFLAGS=-W, the compiling issue will be occured.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/as102/Makefile

@@ -3,4 +3,4 @@ dvb-as102-objs := as102_drv.o as102_fw.o as10x_cmd.o as10x_cmd_stream.o \
 
 obj-$(CONFIG_DVB_AS102) += dvb-as102.o
 
-EXTRA_CFLAGS += -Idrivers/media/dvb-core
+ccflags-y += -Idrivers/media/dvb-core