arm64: dts: qcom: sa8775p: rename bus clock to follow the bindings

arm64: dts: qcom: sa8775p: rename bus clock to follow the bindings

DT bindings for the DPU SA8775P declare the first clock to be "nrt_bus",
not just "bus". Fix the DT file accordingly.

Fixes: 2f39d2d46c73 ("arm64: dts: qcom: sa8775p: add display dt nodes for MDSS0 and DPU")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250602-sa8775p-fix-dts-v1-1-f9f6271b33a3@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>