i2c: stm32: fix usage of rise/fall device tree properties

These two device tree properties were not being applied.

Fixes: 1fd9eb68d6 ("i2c: stm32f7: move driver data of each instance in a privdata")
Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Reviewed-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Tested-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c
index 80bd3c4..836148e 100644
--- a/drivers/i2c/stm32f7_i2c.c
+++ b/drivers/i2c/stm32f7_i2c.c
@@ -914,18 +914,19 @@
 {
 	const struct stm32_i2c_data *data;
 	struct stm32_i2c_priv *i2c_priv = dev_get_priv(dev);
-	u32 rise_time, fall_time;
 	int ret;
 
 	data = (const struct stm32_i2c_data *)dev_get_driver_data(dev);
 	if (!data)
 		return -EINVAL;
 
-	rise_time = dev_read_u32_default(dev, "i2c-scl-rising-time-ns",
-					 STM32_I2C_RISE_TIME_DEFAULT);
+	i2c_priv->setup.rise_time = dev_read_u32_default(dev,
+							 "i2c-scl-rising-time-ns",
+							 STM32_I2C_RISE_TIME_DEFAULT);
 
-	fall_time = dev_read_u32_default(dev, "i2c-scl-falling-time-ns",
-					 STM32_I2C_FALL_TIME_DEFAULT);
+	i2c_priv->setup.fall_time = dev_read_u32_default(dev,
+							 "i2c-scl-falling-time-ns",
+							 STM32_I2C_FALL_TIME_DEFAULT);
 
 	i2c_priv->dnf_dt = dev_read_u32_default(dev, "i2c-digital-filter-width-ns", 0);
 	if (!dev_read_bool(dev, "i2c-digital-filter"))