i2c: fix I2C slave clock source selection

In I2C slave mode, clock source can now be changed, according to
the flags specified in `i2c_config_t` structure. Thus, ESP32-S2
can now act as an I2C slave, even with a 400KHz master clock.

components/hal/include/hal/i2c_hal.h

@@ -110,6 +110,16 @@ typedef struct {
  */
 #define i2c_hal_slave_clr_rx_it(hal)    i2c_ll_slave_clr_rx_it((hal)->dev)
 
+/**
+ * @brief  Set the source clock. This function is meant to be used in
+ *         slave mode, in order to select a source clock abe to handle
+ *         the expected SCL frequency.
+ *
+ * @param  hal Context of the HAL layer
+ * @param  src_clk Source clock to use choosen from `i2c_sclk_t` type
+ */
+#define i2c_hal_set_source_clk(hal, src_clk) i2c_ll_set_source_clk((hal)->dev, src_clk)
+
 /**
  * @brief  Init the I2C master.
  *