liquidio: cn68xx: Remove duplicated include

Remove duplicated include.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20201031024744.39020-1-yuehaibing@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/cavium/liquidio/cn68xx_device.c

@@ -27,7 +27,6 @@
 #include "cn66xx_device.h"
 #include "cn68xx_device.h"
 #include "cn68xx_regs.h"
-#include "cn68xx_device.h"
 
 static void lio_cn68xx_set_dpi_regs(struct octeon_device *oct)
 {