i2c: modify examples to work out of the box on ESP32S3

On ESP32S3, the default I2C pins of the examples are already used by USB.
This commit changes the default pins.

docs/en/api-reference/peripherals/i2c.rst

@@ -148,6 +148,25 @@ When :cpp:member:`i2c_config_t::clk_flags` is 0, the clock allocator will select
     1. :c:macro:`I2C_SCLK_SRC_FLAG_AWARE_DFS`: Clock's baud rate will not change while APB clock is changing.
     2. :c:macro:`I2C_SCLK_SRC_FLAG_LIGHT_SLEEP`: It supports Light-sleep mode, which APB clock cannot do.
 
+.. only:: esp32s3
+
+    .. list-table:: Characteristics of {IDF_TARGET_NAME} clock sources
+       :widths: 5 5 50 20
+       :header-rows: 1
+
+       * - Clock name
+         - Clock frequency
+         - MAX freq for SCL
+         - Clock capabilities
+       * - XTAL clock
+         - 40 MHz
+         - 2 MHz
+         - /
+       * - RTC clock
+         - 20 MHz
+         - 1 MHz
+         - :c:macro:`I2C_SCLK_SRC_FLAG_AWARE_DFS`, :c:macro:`I2C_SCLK_SRC_FLAG_LIGHT_SLEEP`
+
 .. only:: esp32c3
 
     .. list-table:: Characteristics of {IDF_TARGET_NAME} clock sources