hw/net: add support for Allwinner EMAC Fast Ethernet controller

This patch adds support for the Fast Ethernet MAC found on Allwinner
SoCs, together with a basic emulation of Realtek RTL8201CP PHY.

Since there is no public documentation of the Allwinner controller, the
implementation is based on Linux kernel driver.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index ce1d620..f3513fa 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -27,6 +27,7 @@
 CONFIG_SSI_M25P80=y
 CONFIG_LAN9118=y
 CONFIG_SMC91C111=y
+CONFIG_ALLWINNER_EMAC=y
 CONFIG_DS1338=y
 CONFIG_PFLASH_CFI01=y
 CONFIG_PFLASH_CFI02=y