Convert CONFIG_E1000 to Kconfig

This converts the following to Kconfig:
   CONFIG_E1000

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/mvebu_db_armada8k_defconfig b/configs/mvebu_db_armada8k_defconfig
index d9a5759..e6168a7 100644
--- a/configs/mvebu_db_armada8k_defconfig
+++ b/configs/mvebu_db_armada8k_defconfig
@@ -49,6 +49,7 @@
 CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_PHY_MARVELL=y
 CONFIG_PHY_GIGE=y
+CONFIG_E1000=y
 CONFIG_MVPP2=y
 CONFIG_NVME=y
 CONFIG_PCI=y