spi: stm32_qspi: Add st, stm32f469-qspi compatible string

Add "st,stm32f469-qspi" compatible which is used on kernel side.
This will be necessary when DT will be synchronised from kernel.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

drivers/spi/stm32_qspi.c

@@ -635,6 +635,7 @@ static const struct dm_spi_ops stm32_qspi_ops = {
 
 static const struct udevice_id stm32_qspi_ids[] = {
 	{ .compatible = "st,stm32-qspi" },
+	{ .compatible = "st,stm32f469-qspi" },
 	{ }
 };