driver-core: base: 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: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index c12c7f2..5f51c3b 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -19,7 +19,5 @@
 endif
 obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o
 
-ifeq ($(CONFIG_DEBUG_DRIVER),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG