Revert "TCA8418 initial config + basic 3x4 keypad config (#6320)" (#6410)

This reverts commit 13101c1bab.

src/main.cpp

@@ -568,10 +568,6 @@ void setup()
             // assign an arbitrary value to distinguish from other models
             kb_model = 0x37;
             break;
-        case ScanI2C::DeviceType::TCA8418KB:
-            // assign an arbitrary value to distinguish from other models
-            kb_model = 0x84;
-            break;
         default:
             // use this as default since it's also just zero
             LOG_WARN("kb_info.type is unknown(0x%02x), setting kb_model=0x00", kb_info.type);