net: xilinx_axienet.c: Add phy soft reset bit clearing

Clear the BMCR Reset when writing to registers.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
[ PC:
 * Trivial style fixes to commit message
]
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

hw/net/xilinx_axienet.c

@@ -142,6 +142,9 @@ tdk_write(struct PHY *phy, unsigned int req, unsigned int data)
             phy->regs[regnum] = data;
             break;
     }
+
+    /* Unconditionally clear regs[BMCR][BMCR_RESET] */
+    phy->regs[0] &= ~0x8000;
 }
 
 static void