ESP32: Use QIO flash mode by default

This will make access much faster and will work for most of the users.

For those who need to go back to DIO, this can be done as follows:

```
build_vars:
  ESP_IDF_SDKCONFIG_OPTS: >
    ${build_vars.ESP_IDF_SDKCONFIG_OPTS}
    CONFIG_FLASHMODE_QIO=
    CONFIG_FLASHMODE_DIO=y
```

CL: ESP32: Use QIO flash mode by default

PUBLISHED_FROM=a4e2d67f03063df35a25fb002b367ba929d09cc7

fw/platforms/esp32/sdkconfig

@@ -49,3 +49,6 @@ CONFIG_ESP32_XTAL_FREQ_40=
 CONFIG_ESP32_XTAL_FREQ_26=
 CONFIG_ESP32_XTAL_FREQ_AUTO=y
 CONFIG_ESP32_XTAL_FREQ=0
+
+CONFIG_FLASHMODE_DIO=
+CONFIG_FLASHMODE_QIO=y