skge/sky2/mv643xx/pxa168: Move the Marvell Ethernet drivers

Move the Marvell Ethernet drivers into drivers/net/ethernet/marvell/
and make the necessary Kconfig and Makefile changes.

CC: Sachin Sanap <ssanap@marvell.com>
CC: Zhangfei Gao <zgao6@marvell.com>
CC: Philip Rakity <prakity@marvell.com>
CC: Mark Brown <markb@marvell.com>
CC: Lennert Buytenhek <buytenh@marvell.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>