interconnect: icc-rpm: Add support for bus power domain

Add support for attaching to a power domain. This is required
for Aggregate 0 NoC on MSM8996, which is powered by a GDSC.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> #db820c
Link: https://lore.kernel.org/r/20211021132329.234942-3-y.oudjana@protonmail.com


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