media: vimc: Update device configuration in the documentation

Current configuration in the document is outdated and doesn't work. Update
it to match the configuration described in the following commit:

commit 9b4a9b31 ("media: vimc: Enable set resolution at the scaler src pad")

Fixed commit description:
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: Dafna Hirschfeld <dafna@fastmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>