arm: bcm281xx: add board with Ethernet capability

Add board which has Broadcom StarFighter2 Ethernet capability.

Signed-off-by: Steve Rae <srae@broadcom.com>

board/broadcom/bcm28155_w1d/MAINTAINERS

@@ -0,0 +1,6 @@
+BCM28155_W1D BOARD
+M:	Steve Rae <srae@broadcom.com>
+S:	Maintained
+F:	board/broadcom/bcm28155_ap/
+F:	include/configs/bcm28155_ap.h
+F:	configs/bcm28155_w1d_defconfig

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