dts: socfpga: Add DTS entry for adding the stmmac glue layer for stmmac.

This patch adds the dts bindings documenation for the Altera SOCFPGA glue
layer for the Synopsys STMMAC ethernet driver.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --cc Documentation/devicetree/bindings/net/socfpga-dwmac.txt
Simple merge

diff --cc arch/arm/boot/dts/socfpga.dtsi
Simple merge

diff --cc arch/arm/boot/dts/socfpga_arria5_socdk.dts
Simple merge

diff --cc arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
Simple merge

diff --cc arch/arm/boot/dts/socfpga_cyclone5_sockit.dts
Simple merge

diff --cc arch/arm/boot/dts/socfpga_vt.dts
Simple merge