mmc: host: sdhci-msm: Use the interconnect API

The interconnect API provides an interface for consumer drivers to express
their bandwidth needs in the SoC. This data is aggregated and the on-chip
interconnect hardware is configured to the most appropriate power/performance
profile.

Use the interconnect API to get() the path between the endpoints used for
data transfers by the SD host controller and report the needed bandwidth based
on the clock rate, bus width and mode.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>