mmc: meson-gx: Add AXG compatible

Add the compatible string for the upcoming Amlogic AXG SoC family.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/mmc/meson_gx_mmc.c b/drivers/mmc/meson_gx_mmc.c
index 332f1e1..767dfff 100644
--- a/drivers/mmc/meson_gx_mmc.c
+++ b/drivers/mmc/meson_gx_mmc.c
@@ -278,6 +278,7 @@
 
 static const struct udevice_id meson_mmc_match[] = {
 	{ .compatible = "amlogic,meson-gx-mmc" },
+	{ .compatible = "amlogic,meson-axg-mmc" },
 	{ /* sentinel */ }
 };