arm64: dts: qcom: sm8550: Limit max SD HS mode frequency by default

arm64: dts: qcom: sm8550: Limit max SD HS mode frequency by default

Due to an implementation detail in this SoC, additional passive
electrical components are required to achieve the maximum rated speed
of the SD controller when paired with a High-Speed SD Card. Without
them, the clock frequency must be limited to 37.5 MHz for link stability.

Because the reference design does not contain these components, most
(derivative) boards do not have them either. To accommodate for that,
apply the frequency limit by default and delegate lifting it to the
odd boards that do contain the necessary onboard hardware.

Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250908104122.2062653-5-quic_sartgarg@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>