NET: move legacy enc28j60.c to sidetrack as enc28j60_lpc2292.c

This patch is required before the upcoming new enc28j60 driver
using SPI framework patch can be applied:
- Move legacy enc28j60.c to enc28j60_lpc2292.c.
- Change Makefile and the two affected boards' definition files.

Tested with ./MAKEALL ARM7 that both boards still compile.

Signed-off-by: Reinhard Meyer<info@emk-elektronik.de>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 218eeff..479954d 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -39,7 +39,7 @@
 COBJS-$(CONFIG_DNET) += dnet.o
 COBJS-$(CONFIG_E1000) += e1000.o
 COBJS-$(CONFIG_EEPRO100) += eepro100.o
-COBJS-$(CONFIG_ENC28J60) += enc28j60.o
+COBJS-$(CONFIG_ENC28J60_LPC2292) += enc28j60_lpc2292.o
 COBJS-$(CONFIG_EP93XX) += ep93xx_eth.o
 COBJS-$(CONFIG_ETHOC) += ethoc.o
 COBJS-$(CONFIG_FEC_MXC) += fec_mxc.o