interconnect: qcom: Consolidate interconnect RPMh support

Add bcm voter driver and add support for RPMh specific interconnect
providers which implements the set and aggregate functionalities that
translates bandwidth requests into RPMh messages. These modules provide
a common set of functionalities for all Qualcomm RPMh based interconnect
providers and should help reduce code duplication when adding new
providers.

Signed-off-by: David Dai <daidavid1@codeaurora.org>
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200228095951.15457-1-sibis@codeaurora.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>