boards: adafruit_feather_stm32f405: Fix Feather Header pins

The mapping was taken from
https://learn.adafruit.com/adafruit-stm32f405-feather-express/pinouts

| Name / GPIO |  | current mapping | correction |
| ------------- | ------------- | ----- | --- |
| RX / GPIO 0  | PB11 | `&gpiob 11` |
| TX / GPIO 1 | PB10 | `&gpiob 10` |
| SDA / GPIO 14 | PB7 | `&gpiob 7` |
| SCL / GPIO 15 | PB6 | `&gpiob 6` |
| GPIO 5 | PC7 | `&gpioc 7` |
| GPIO 6 | PC6 | `&gpioc 6` |
| GPIO 9 | PB8 | `&gpioc 5` ❌ | **`&gpiob 8`** |
| GPIO 10 | PB9 | `&gpioc 4` ❌

 | **`&gpiob 9`** |
| GPIO 11 | PC3 | `&gpioc 3` |
| GPIO 12 | PC2 | `&gpioc 2` |
| GPIO 13 | PC1 |  `&gpioc 1` |
| SCK / GPIO23 | PB13 | `&gpiob 13` |
| MISO / GPIO24 | PB14 | `&gpiob 14` |
| MOSI / GPIO25 | PB15 | `&gpiob 15` |
| A0 / GPIO 16 | PA4 | `&gpioa 4` |
| A1 / GPIO 17 | PA5 | `&gpioa 5` |
| A2 / GPIO18 | PA6 | `&gpioa 6` |
| A3 / GPIO19 | PA7 | `&gpioa 7` |
| A4 / GPIO20 | PC4 | `&gpioc 4` |
| A5 / GPIO21 | PC5 | `&gpioc 5` |

closes #33326

Signed-off-by: Maximilian Huber <gh@maxhbr.de>