interconnect: qcom: osm-l3: fix registration race

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail:

	of_icc_xlate_onecell: invalid index 0
	cpu cpu0: error -EINVAL: error finding src node
	cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
	qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 5bc9900a

 ("interconnect: qcom: Add OSM L3 interconnect provider support")
Cc: stable@vger.kernel.org      # 5.7
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230306075651.2449-6-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>