bridge: make br_device_notifier static

Merge net/bridge/br_notify.c into net/bridge/br.c,
since it has only br_device_event() and br.c is small.

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/Makefile b/net/bridge/Makefile
index 906a18b..29b6e2a 100644
--- a/net/bridge/Makefile
+++ b/net/bridge/Makefile
@@ -5,7 +5,7 @@
 obj-$(CONFIG_BRIDGE) += bridge.o
 
 bridge-y	:= br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
-			br_ioctl.o br_notify.o br_stp.o br_stp_bpdu.o \
+			br_ioctl.o br_stp.o br_stp_bpdu.o \
 			br_stp_if.o br_stp_timer.o br_netlink.o
 
 bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o