net: designware: add meson meson gxbb compatible

Add the compatible string for the Amlogic GXBB SoC family.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 19db0a8..cdcc03f 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -838,6 +838,7 @@
 	{ .compatible = "altr,socfpga-stmmac" },
 	{ .compatible = "amlogic,meson6-dwmac" },
 	{ .compatible = "amlogic,meson-gx-dwmac" },
+	{ .compatible = "amlogic,meson-gxbb-dwmac" },
 	{ .compatible = "st,stm32-dwmac" },
 	{ }
 };