Fix sdcard image creation with dosfstools >= 4.2
Fix sdcard image creation with dosfstools >= 4.2

It seems elder versions ignored labels with more than 11 chars. Now we get:

| mkfs.vfat: Label can be no longer than 11 characters
| mkfs.fat 4.2 (2021-01-31)

Signed-off-by: Andreas Müller <d72a15aaaca3a7afa855175c72dc8d2e05931e32@gmail.com>

schnitzeltony/meta-raspi-light,schnitzeltony/meta-raspi-light