docs/esp32: Update pin access example with addresses for ESP32-S3.

Signed-off-by: Paul Grayson <pdg@alum.mit.edu>
Signed-off-by: Angus Gratton <angus@redyak.com.au>

docs/esp32/tutorial/peripheral_access.rst

@@ -32,6 +32,18 @@ the prescaler of the MCPWM0 peripheral.
     mem32[MCPWM0] = 0x55      # change PWM_CLK_PRESCALE
     print(hex(mem32[MCPWM0])) # read PWM_CLK_CFG_REG
 
+The specific addresses will be different on different ESP32
+models. For example, ESP32-S3 uses these values:
+
+.. code-block:: python3
+
+    DR_REG_DPORT_BASE = const(0x600C_0000)
+    DPORT_PERIP_CLK_EN0_REG = const(DR_REG_DPORT_BASE + 0x0018)
+    DPORT_PERIP_RST_EN0_REG = const(DR_REG_DPORT_BASE + 0x0020)
+    DPORT_PWM0_CLK_EN = const(1 << 17)
+    MCPWM0 = const(0x6001_E000 + 0x0004)
+    ...
+
 Note that before a peripheral can be used its clock must be enabled and it must
 be taken out of reset.  In the above example the following registers are used
 for this: