arm64: dts: qcom: sm8650: add the missing l2 cache node

Only two little a520s share the same L2, every a720 has their own L2
cache.

Fixes: d2350377 ("arm64: dts: qcom: add initial SM8650 dtsi")
Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250405105529.309711-1-mitltlatltl@gmail.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>