media: Don't default-enable "ancillary driver autoselect" if EMBEDDED

Admittedly, it's not easy to say what CONFIG_EMBEDDED really should be
doing, just as it's not easy to say what is "embedded".

In any case, the very description of MEDIA_SUBDRV_AUTOSELECT
specifies that embedded systems usually don't want
to enable this autoselect option.

Therefore, drop the default-yes, when the CONFIG_EMBEDDED is chosen.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>