meta-aspeed: g6: defconfig: Enable I2C GPIO mux

Some platforms make use of it.

Change-Id: I13b91299039b2d435581fed51ac7894c7d7f9544
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig b/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
index 2ef9ba0..d62b3a9 100644
--- a/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
+++ b/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
@@ -157,6 +157,7 @@
 # CONFIG_I2C_COMPAT is not set
 CONFIG_I2C_CHARDEV=y
 CONFIG_I2C_MUX=y
+CONFIG_I2C_MUX_GPIO=y
 CONFIG_I2C_MUX_PCA9541=y
 CONFIG_I2C_MUX_PCA954x=y
 CONFIG_I2C_ASPEED=y