drivers/net/vsc9953: Add commands to enable/disable HW learning

The command:
ethsw [port <port_no>] learning { [help] | show | auto | disable }

can be used to enable/disable HW learning on a port.
This patch also adds this command to the generic ethsw parser from
cmd_ethsw.

Signed-off-by: Johnson Leung <johnson.leung@freescale.com>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/vsc9953.h b/include/vsc9953.h
index 83c4c89..49215e6 100644
--- a/include/vsc9953.h
+++ b/include/vsc9953.h
@@ -105,6 +105,12 @@
 #define VSC9953_VLAN_CMD_WRITE		0x00000002
 #define VSC9953_VLAN_CMD_INIT		0x00000003
 
+/* Macros for vsc9953_ana_port.port_cfg register */
+#define VSC9953_PORT_CFG_LEARN_ENA	0x00000080
+#define VSC9953_PORT_CFG_LEARN_AUTO	0x00000100
+#define VSC9953_PORT_CFG_LEARN_CPU	0x00000200
+#define VSC9953_PORT_CFG_LEARN_DROP	0x00000400
+
 /* Macros for vsc9953_qsys_sys.switch_port_mode register */
 #define VSC9953_PORT_ENA		0x00002000