arm64: dts: qcom: sm8550: Fix xo clock supply of platform SD host controller

arm64: dts: qcom: sm8550: Fix xo clock supply of platform SD host controller

The expected frequency of SD host controller core supply clock is 19.2MHz,
while RPMH_CXO_CLK clock frequency on SM8650 platform is 38.4MHz.

Apparently the overclocked supply clock could be good enough on some
boards and even with the most of SD cards, however some low-end UHS-I
SD cards in SDR104 mode of the host controller produce I/O errors in
runtime, fortunately this problem is gone, if the "xo" clock frequency
matches the expected 19.2MHz clock rate.

Fixes: ffc50b2d3828 ("arm64: dts: qcom: Add base SM8550 dtsi")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20260314023715.357512-2-vladimir.zapolskiy@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>