drivers/net/irda/Kconfig: Let SH_IRDA depend on HAS_IOMEM

SH_IRDA needs HAS_IOMEM, so depend on it. The related error(with
allmodconfig under um):

    CC [M]  drivers/net/irda/sh_irda.o
  drivers/net/irda/sh_irda.c: In function ‘sh_irda_probe’:
  drivers/net/irda/sh_irda.c:776:2: error: implicit declaration of function ‘ioremap_nocache’ [-Werror=implicit-function-declaration]
    self->membase = ioremap_nocache(res->start, resource_size(res));
    ^
  drivers/net/irda/sh_irda.c:776:16: warning: assignment makes pointer from integer without a cast [enabled by default]
    self->membase = ioremap_nocache(res->start, resource_size(res));
                  ^
  drivers/net/irda/sh_irda.c:821:2: error: implicit declaration of function ‘iounmap’ [-Werror=implicit-function-declaration]
    iounmap(self->membase);
    ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>