pps: 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>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
index 42517da..4feb7e9 100644
--- a/drivers/pps/clients/Makefile
+++ b/drivers/pps/clients/Makefile
@@ -6,6 +6,4 @@
 obj-$(CONFIG_PPS_CLIENT_LDISC)	+= pps-ldisc.o
 obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o
 
-ifeq ($(CONFIG_PPS_DEBUG),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG