configs: stm32mp1: activate Ethernet PHY Realtek

Need Realtek driver to manage in RTL8211F the configuration of the LED.
Initialize LCR (LED Control Register) to configure green LED for Link,
yellow LED for Active

Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index cdcf591c..e5d9e8b 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -97,6 +97,7 @@
 # CONFIG_SPI_FLASH_USE_4K_SECTORS is not set
 CONFIG_SPI_FLASH_MTD=y
 CONFIG_SPL_SPI_FLASH_MTD=y
+CONFIG_PHY_REALTEK=y
 CONFIG_DM_ETH=y
 CONFIG_DWC_ETH_QOS=y
 CONFIG_PHY=y