docs: remove A316 firmware FAQ entries

en/docs/dev_doc/faq/technical_faq/a316_firmware_dev_faq.md

@@ -47,31 +47,6 @@ keywords: A316 firmware development, XU316 communication issues, USB device powe
 
 </div>
 
-### Q2: Sending I2S IN command is ineffective when WiFi is in slave mode
-
-<div class="grid" markdown>
-
-=== "Problem Symptoms"
-    1. After normal wiring and power-up, current mode shows USB, but sending I2S IN command has no effect
-
-=== "Possible Causes"
-    1. Firmware function limitations
-        - Current firmware does not support mode switching from WiFi (I2S slave) to XMOS (I2S master)
-
-=== "Problem Analysis"
-    1. Communication status
-        - Commands can communicate normally
-        - But mode switching function does not take effect
-    2. Function limitations
-        - Firmware has not implemented conversion function from WiFi slave mode to XMOS master mode
-
-=== "Solutions"
-    1. Modify connection method
-        - Mount WiFi module to Bluetooth module
-        - Implement mode switching function through Bluetooth module
-
-</div>
-
 ## Device Recognition Issues
 
 ### Q1: Device is recognized and plays normally on PC, but mobile phone cannot recognize device