remoteproc: qcom: q6v5: Add interconnect path proxy vote

Many remoteproc instances requires that Linux casts a proxy vote for an
interconnect path during boot, until they can do it themselves. Add
support for voting for a single path.

As this is a shared problem between both PAS and MSS drivers, the path
is acquired and votes casted from the common helper code.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20220225033224.2238425-1-bjorn.andersson@linaro.org