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/xilinx_zynqmp_kria_defconfig b/configs/xilinx_zynqmp_kria_defconfig
index ba42f0c..8c60325 100644
--- a/configs/xilinx_zynqmp_kria_defconfig
+++ b/configs/xilinx_zynqmp_kria_defconfig
@@ -158,6 +158,7 @@
 CONFIG_SPI_FLASH_STMICRO=y
 # CONFIG_SPI_FLASH_USE_4K_SECTORS is not set
 CONFIG_SPI_FLASH_MTD=y
+CONFIG_PHY_ANEG_TIMEOUT=20000
 CONFIG_PHY_ADIN=y
 CONFIG_PHY_TI_DP83867=y
 CONFIG_PHY_XILINX_GMII2RGMII=y