net: Add MSCC Serval network driver.

Add network driver for Microsemi Ethernet switch.
It is present on Serval SoCs.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/drivers/net/mscc_eswitch/Kconfig b/drivers/net/mscc_eswitch/Kconfig
index 6359d0b..80dd22f 100644
--- a/drivers/net/mscc_eswitch/Kconfig
+++ b/drivers/net/mscc_eswitch/Kconfig
@@ -29,3 +29,10 @@
 	select PHYLIB
 	help
 	  This driver supports the Servalt network switch device.
+
+config MSCC_SERVAL_SWITCH
+	bool "Serval switch driver"
+	depends on DM_ETH && ARCH_MSCC
+	select PHYLIB
+	help
+	  This driver supports the Serval network switch device.