mmc: sdhci-msm: Add interconnect bandwidth scaling support

Interconnect bandwidth scaling support is now added as a
part of OPP. So, make sure interconnect driver is ready
before handling interconnect scaling.

Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/1591691846-7578-2-git-send-email-ppvk@codeaurora.org


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>