arm64: defconfig: enable Allwinner DMA drivers

Allwinner sun6i DMA drivers is used on A64 and H6 boards.

Enable it as a module.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm64/configs/defconfig

@@ -615,6 +615,7 @@ CONFIG_RTC_DRV_IMX_SC=m
 CONFIG_RTC_DRV_XGENE=y
 CONFIG_DMADEVICES=y
 CONFIG_DMA_BCM2835=m
+CONFIG_DMA_SUN6I=m
 CONFIG_K3_DMA=y
 CONFIG_MV_XOR=y
 CONFIG_MV_XOR_V2=y