interconnect: qcom: icc-rpm: allow overwriting get_bw callback

interconnect: qcom: icc-rpm: allow overwriting get_bw callback

MSM8974 requires a separate get_bw callback, since on that platform
increasing the clock rate for some of the NoCs during boot may lead to
hangs. For the details see commit 9caf2d956cfa ("interconnect: qcom:
msm8974: Don't boost the NoC rate during boot").

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://msgid.link/20260324-msm8974-icc-v2-4-527280043ad8@oss.qualcomm.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>