net: Remove eth_legacy.c

As there are no more non-DM_ETH cases for networking, remove this legacy
file and update the Makefile to match current usage.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/net/Makefile b/net/Makefile
index 13eef04..bea000b 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -10,18 +10,14 @@
 obj-$(CONFIG_CMD_CDP)  += cdp.o
 obj-$(CONFIG_CMD_DNS)  += dns.o
 obj-$(CONFIG_DM_DSA)   += dsa-uclass.o
-ifdef CONFIG_DM_ETH
-obj-$(CONFIG_NET)      += eth-uclass.o
+obj-$(CONFIG_$(SPL_)DM_ETH) += eth-uclass.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTDEV_ETH) += eth_bootdev.o
-else
-obj-$(CONFIG_NET)      += eth_legacy.o
-endif
 obj-$(CONFIG_DM_MDIO)  += mdio-uclass.o
 obj-$(CONFIG_DM_MDIO_MUX) += mdio-mux-uclass.o
-obj-$(CONFIG_NET)      += eth_common.o
+obj-$(CONFIG_$(SPL_)DM_ETH) += eth_common.o
 obj-$(CONFIG_CMD_LINK_LOCAL) += link_local.o
 obj-$(CONFIG_IPV6)     += ndisc.o
-obj-$(CONFIG_NET)      += net.o
+obj-$(CONFIG_$(SPL_)DM_ETH) += net.o
 obj-$(CONFIG_IPV6)     += net6.o
 obj-$(CONFIG_CMD_NFS)  += nfs.o
 obj-$(CONFIG_CMD_PING) += ping.o