sh_eth: add missing EESIPR bits

Renesas SH77{34|63} manuals  describe more EESIPR bits than the current
driver. Declare the new bits with the end goal of using the bit names
instead of the bare numbers  for  the 'sh_eth_cpu_data::eesipr_value'
initializers...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>