orion: Enable CONFIG_MV_XOR

This is helpful for Orion-based NAS boxes that have the XOR engine enabled
since it provides faster software RAID.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

target/linux/orion/config-4.4

@@ -98,6 +98,7 @@ CONFIG_DEBUG_UNCOMPRESS=y
 # CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set
 CONFIG_DEVMEM=y
 CONFIG_DNOTIFY=y
+CONFIG_DMADEVICES=y
 # CONFIG_DP83848_PHY is not set
 # CONFIG_DP83867_PHY is not set
 # CONFIG_DST_CACHE is not set
@@ -276,6 +277,7 @@ CONFIG_MVEBU_MBUS=y
 CONFIG_MVMDIO=y
 # CONFIG_MVNETA is not set
 # CONFIG_MVNETA_BM is not set
+CONFIG_MV_XOR=y
 CONFIG_NEED_DMA_MAP_STATE=y
 CONFIG_NEED_KUSER_HELPERS=y
 CONFIG_NEED_PER_CPU_KM=y