forcedeth: Move the NVIDIA nForce driver

Move the nForce driver into drivers/net/ethernet/nvidia/ and make
the necessary Kconfig and Makefile changes.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/Makefile

@@ -28,7 +28,6 @@ obj-$(CONFIG_SH_ETH) += sh_eth.o
 obj-$(CONFIG_NET) += Space.o loopback.o
 obj-$(CONFIG_NET_SB1000) += sb1000.o
 obj-$(CONFIG_HP100) += hp100.o
-obj-$(CONFIG_FORCEDETH) += forcedeth.o
 
 obj-$(CONFIG_PPP) += ppp_generic.o
 obj-$(CONFIG_PPP_ASYNC) += ppp_async.o