configs: ls1046ardb: enable PHY_FIXED

The optical 10G port is described as fixed-link in the device tree. Enable
the necessary support.

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/ls1046ardb_qspi_SECURE_BOOT_defconfig b/configs/ls1046ardb_qspi_SECURE_BOOT_defconfig
index bf7dbe7..7f1848d 100644
--- a/configs/ls1046ardb_qspi_SECURE_BOOT_defconfig
+++ b/configs/ls1046ardb_qspi_SECURE_BOOT_defconfig
@@ -43,6 +43,7 @@
 CONFIG_PHYLIB=y
 CONFIG_PHY_AQUANTIA=y
 CONFIG_PHY_REALTEK=y
+CONFIG_PHY_FIXED=y
 CONFIG_DM_ETH=y
 CONFIG_DM_MDIO=y
 CONFIG_E1000=y