arm: bcm281xx: Add Ethernet Clock support

Enable Ethernet clock when Broadcom StarFighter2 Ethernet block
(CONFIG_BCM_SF2_ETH) is enabled.

Signed-off-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Steve Rae <srae@broadcom.com>
diff --git a/arch/arm/cpu/armv7/bcm281xx/Makefile b/arch/arm/cpu/armv7/bcm281xx/Makefile
index 98f5aa5..bd867a2 100644
--- a/arch/arm/cpu/armv7/bcm281xx/Makefile
+++ b/arch/arm/cpu/armv7/bcm281xx/Makefile
@@ -9,3 +9,4 @@
 obj-y	+= clk-bcm281xx.o
 obj-y	+= clk-sdio.o
 obj-y	+= clk-bsc.o
+obj-$(CONFIG_BCM_SF2_ETH) += clk-eth.o