net: Move CONFIG_E1000 options to Kconfig

Move config for the E1000 Ethernet driver to Kconfig and tidy up affected
boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/T1023RDB_defconfig b/configs/T1023RDB_defconfig
index 8ff03a5..c4b72d4 100644
--- a/configs/T1023RDB_defconfig
+++ b/configs/T1023RDB_defconfig
@@ -3,3 +3,5 @@
 CONFIG_TARGET_T102XRDB=y
 CONFIG_SYS_EXTRA_OPTIONS="PPC_T1023,T1023RDB"
 CONFIG_SPI_FLASH=y
+CONFIG_NETDEVICES=y
+CONFIG_E1000=y