sh_eth: get rid of {cpu|edmac}_to_{edmac|cpu}()

Now that {cpu|edmac}_to_{edmac|cpu}() functions boiled down to the mere
{cpu|le32}_to_{le32|cpu}() calls, there's no need for these functions
anymore, so just get rid of them.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>