arm: bcm281xx: add board with Ethernet capability

Add board which has Broadcom StarFighter2 Ethernet capability.

Signed-off-by: Steve Rae <srae@broadcom.com>
diff --git a/configs/bcm28155_w1d_defconfig b/configs/bcm28155_w1d_defconfig
new file mode 100644
index 0000000..94b791c
--- /dev/null
+++ b/configs/bcm28155_w1d_defconfig
@@ -0,0 +1,3 @@
+CONFIG_SYS_EXTRA_OPTIONS="BCM_SF2_ETH,BCM_SF2_ETH_GMAC"
+CONFIG_ARM=y
+CONFIG_TARGET_BCM28155_AP=y