interconnect: qcom: osm-l3: Mark more structures const

interconnect: qcom: osm-l3: Mark more structures const

These structures aren't modified at runtime. Mark them const so they get
moved to read-only memory. We have to cast away const in one place when
we store into the data member of struct icc_node. This is paired with a
re-const of the data member when it is extracted in qcom_icc_set().

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20200914182112.513981-1-swboyd@chromium.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>