firmware: qcom: scm: Remove core, iface and bus clocks dependency

Core, iface and bus clocks are not required to be voted from SCM
driver for some of the Qualcomm chipsets. Remove dependency on
these clocks from driver.

Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>