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/P4080DS_SRIO_PCIE_BOOT_defconfig b/configs/P4080DS_SRIO_PCIE_BOOT_defconfig
index b3f6b69..766db5e 100644
--- a/configs/P4080DS_SRIO_PCIE_BOOT_defconfig
+++ b/configs/P4080DS_SRIO_PCIE_BOOT_defconfig
@@ -5,3 +5,5 @@
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_SPI_FLASH=y
+CONFIG_NETDEVICES=y
+CONFIG_E1000=y