sh_eth: get SH77{34|63} support out of #ifdef

Get the SH77{34|63} specific code/data in the driver out of #ifdef by adding
"sh7734-gether" and "sh7763-gether" to the platform driver's ID table.  Note
that we have to split the 'struct sh_eth_cpu_data' instance into two due to
#ifdef inside it; note that we can kill the duplicate sh_eth_set_rate_gether().
Change the GEther platform device's name in the SH platform code accordingly.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>