net: phy: Replace PHY_ANEG_TIMEOUT with Kconfig symbol

Switch PHY_ANEG_TIMEOUT to CONFIG_PHY_ANEG_TIMEOUT Kconfig symbol.
This removes one more configuration headers option finalizes its
Kconfig symbol conversion. No functional change expected.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/configs/am43xx_evm_defconfig b/configs/am43xx_evm_defconfig
index e1f0ab4..d73b1cb 100644
--- a/configs/am43xx_evm_defconfig
+++ b/configs/am43xx_evm_defconfig
@@ -74,6 +74,7 @@
 CONFIG_SYS_NAND_U_BOOT_LOCATIONS=y
 CONFIG_SYS_NAND_U_BOOT_OFFS=0x180000
 CONFIG_SPI_FLASH_MACRONIX=y
+CONFIG_PHY_ANEG_TIMEOUT=8000
 CONFIG_PHY_GIGE=y
 CONFIG_MII=y
 CONFIG_DRIVER_TI_CPSW=y