Most MSM8916/MSM8939 devices use very similar setups for the modem,
because most of the device-specific details are abstracted by the modem
firmware. There are several definitions (status switches, DAI links
etc) that will be exactly the same for every board.

Introduce a common msm8916-modem-qdsp6.dtsi include that can be used to
simplify enabling the modem for such devices. By default the
digital/analog codec in the SoC/PMIC is used, but boards can define
additional codecs by adding additional backend DAI links.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20231003-msm8916-modem-v2-4-61b684be55c0@gerhold.netSigned-off-by: Bjorn Andersson <andersson@kernel.org>