gpio: mlxbf2: remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200408070832.137037-1-yuehaibing@huawei.com


Acked-by: Asmaa Mnebhi <Asmaa@mellanox.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>