media: qcom: camss: remove .link_entities callback

There is no potential for a custom .link_entities callback, remove it
by replacing with a common camss_link_entities().

Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Tested-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
[bod: amended for qcm2290, qcs8300, sa8775p]
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>