net: sh-eth: fix inl and outl definitions

The macros inl and outl maybe already be defined from file
arch/arm/include/asm/io.h so there may be no reason to define them.
And if you do try defined them here, you get a redefined complier warning.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Acked-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>