r8169: incorrect identifier for a 8168dp

Merge error.

See CFG_METHOD_8 (0x3c800000 + 0x00300000) since version 8.002.00
of Realtek's driver.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Hayes <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>