CS89x0 : remove QQ2440 board support from the CS89x0 driver

The QQ2440 board isn't supported anymore in the kernel, so support
for this board can be removed from the CS89x0 driver.

Signed-off-by: Jaccon Bastiaansen <jaccon.bastiaansen@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>