arm64: dts: qcom: msm8939: Add QDSP6

arm64: dts: qcom: msm8939: Add QDSP6

MSM8939 does not have a dedicated ADSP. Instead, the audio services via
APR are also implemented by the modem DSP. Audio can be either routed
via the modem DSP (necessary for voice call audio etc) or directly sent
to the LPASS hardware (currently used by DB410c). Bypassing QDSP6 audio
is only possible with special firmware (on DB410c) or when the modem
DSP is completely disabled.

Add the typical nodes for QDSP6 audio to msm8939.dtsi. The apr node is
disabled by default to avoid changing behavior for devices like
apq8039-t2 that use the bypassed audio path.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20231003-msm8916-modem-v2-3-61b684be55c0@gerhold.net
Signed-off-by: Bjorn Andersson <andersson@kernel.org>