interconnect: qcom: sc7180: fix dropped const of qcom_icc_bcm

Pointers to struct qcom_icc_bcm are const, but the change was dropped
during merge.

Fixes: 016fca59

 ("Merge branch 'icc-const' into icc-next")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221027154848.293523-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>