boot_serial: espressif: ESP32-S3 serial recovery mode interface

Add the serial adapter for ESP32-S3 for boot recovery and MCUMGR
communication.

Signed-off-by: Almir Okato <almir.okato@espressif.com>
diff --git a/docs/readme-espressif.md b/docs/readme-espressif.md
index 354854f..ae88987 100644
--- a/docs/readme-espressif.md
+++ b/docs/readme-espressif.md
@@ -552,7 +552,7 @@
 ---
 ***Note***
 
-Supported on ESP32, ESP32-C3, ESP32-S2.
+Supported on ESP32, ESP32-C3, ESP32-S2 and ESP32-S3.
 
 ---