firmware: qcom: scm: Simplify with of_machine_device_match()

firmware: qcom: scm: Simplify with of_machine_device_match()

Replace open-coded getting root OF node and matching against it with
new of_machine_device_match() helper.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patch.msgid.link/20251112-b4-of-match-matchine-data-v2-6-d46b72003fd6@linaro.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>