can: sja1000: remove duplicated includes

Remove duplicated #include('s) in
  drivers/net/can/sja1000/sja1000.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>