Merge branch 'icc-get-by-index' into icc-next

This is an immutable branch shared with the OPP tree. It contains also
the patches to convert the interconnect framework from tristate to bool
after Greg agreed with that. This will make the integration between
the OPP layer and interconnect much easier.

* icc-get-by-index:
  interconnect: Add of_icc_get_by_index() helper function
  interconnect: Disallow interconnect core to be built as a module
  interconnect: Remove unused module exit code from core

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