ftgmac100/ftmac100: Move the Faraday drivers

Move the Faraday driver into drivers/net/ethernet/faraday/ and
make the necessary Kconfig and Makefile changes.

CC: "Po-Yu Chuang" <ratbert@faraday-tech.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Po-Yu Chuang <ratbert@faraday-tech.com>