myri*: Move the Myricom drivers

Move the Myricom drivers into drivers/net/ethernet/myricom/ and make
the necessary Kconfig and Makefile changes.

CC: Andrew Gallatin <gallatin@myri.com>
CC: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>