drivers: net: add Layerscape mEMAC MDIO driver

Add a driver for the MDIO interface integrated in the mEMAC (Multi-rate
Ethernet Media Access Controller) and the Fman 10G Ethernet MACs.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 4d1013c..bc518f2 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -640,4 +640,11 @@
 
 	  This driver is used by the MVPP2 and MVNETA drivers.
 
+config FSL_LS_MDIO
+	bool "NXP Layerscape MDIO interface support"
+	depends on DM_MDIO
+	help
+	  This driver supports the MDIO bus found on the Fman 10G Ethernet MACs and
+	  on the mEMAC (which supports both Clauses 22 and 45).
+
 endif # NETDEVICES