linux-aspeed: Enable XDMA

Somehow this was not enabled. It is required for Witherspoon 128, Tacoma
and Rainier.

(From meta-aspeed rev: a7bbd475453768037877c820caed02f39055eb6e)

Change-Id: Ie80479aa455c18c921387b23586cff3e7bc79204
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
index d62b3a9..4aa6b04 100644
--- a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
+++ b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
@@ -236,6 +236,7 @@
 CONFIG_ASPEED_LPC_CTRL=y
 CONFIG_ASPEED_LPC_SNOOP=y
 CONFIG_ASPEED_P2A_CTRL=y
+CONFIG_ASPEED_XDMA=y
 CONFIG_IIO=y
 CONFIG_ASPEED_ADC=y
 CONFIG_MAX1363=y