ARM: mvebu: Convert CONFIG_MVNETA to Kconfig

This converts the following to Kconfig:
   CONFIG_MVNETA

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/configs/turris_omnia_defconfig b/configs/turris_omnia_defconfig
index a3834ac..870cfd51 100644
--- a/configs/turris_omnia_defconfig
+++ b/configs/turris_omnia_defconfig
@@ -33,8 +33,8 @@
 CONFIG_ATSHA204A=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_MV=y
-CONFIG_PHYLIB=y
 CONFIG_PHY_GIGE=y
+CONFIG_MVNETA=y
 CONFIG_DEBUG_UART_BASE=0xd0012000
 CONFIG_DEBUG_UART_CLOCK=250000000
 CONFIG_DEBUG_UART_SHIFT=2