imx6: add DSA driver for MV88E6176 switch

The MV88E6176 switch is present on the GW16083 and the GW5904

As of a5c32a1f these drivers are to be
enabled static in per-target kernels.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

target/linux/imx6/config-4.9

@@ -352,8 +352,16 @@ CONFIG_MUTEX_SPIN_ON_OWNER=y
 CONFIG_MXS_DMA=y
 CONFIG_NEED_DMA_MAP_STATE=y
 CONFIG_NEON=y
+CONFIG_NET_DSA=y
+# CONFIG_B53 is not set
+CONFIG_NET_DSA_MV88E6XXX=y
+CONFIG_NET_DSA_MV88E6XXX_GLOBAL2=y
+# CONFIG_NET_DSA_QCA8K is not set
+CONFIG_NET_DSA_TAG_DSA=y
+CONFIG_NET_DSA_TAG_EDSA=y
 CONFIG_NET_FLOW_LIMIT=y
 CONFIG_NET_PTP_CLASSIFY=y
+CONFIG_NET_SWITCHDEV=y
 CONFIG_NLS=y
 CONFIG_NLS_CODEPAGE_437=y
 CONFIG_NO_BOOTMEM=y