hw/net/xilinx_axienet: Remove unused code

Most of the MDIOBus fields are unused.  The ADVERTISE_10HALF
definition is unused.  Remove unused code.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-Id: <20200814133007.16850-1-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

hw/net/xilinx_axienet.c

@@ -54,7 +54,6 @@
      TYPE_XILINX_AXI_ENET_CONTROL_STREAM)
 
 /* Advertisement control register. */
-#define ADVERTISE_10HALF        0x0020  /* Try for 10mbps half-duplex  */
 #define ADVERTISE_10FULL        0x0040  /* Try for 10mbps full-duplex  */
 #define ADVERTISE_100HALF       0x0080  /* Try for 100mbps half-duplex */
 #define ADVERTISE_100FULL       0x0100  /* Try for 100mbps full-duplex */
@@ -169,28 +168,6 @@ tdk_init(struct PHY *phy)
 }
 
 struct MDIOBus {
-    /* bus.  */
-    int mdc;
-    int mdio;
-
-    /* decoder.  */
-    enum {
-        PREAMBLE,
-        SOF,
-        OPC,
-        ADDR,
-        REQ,
-        TURNAROUND,
-        DATA
-    } state;
-    unsigned int drive;
-
-    unsigned int cnt;
-    unsigned int addr;
-    unsigned int opc;
-    unsigned int req;
-    unsigned int data;
-
     struct PHY *devs[32];
 };