soc: samsung: chipid: Drop "syscon" compatible requirement

As we dropped the requirement of "syscon" compatible in the chipid
nodes rework code acquiring the regmap to use device_node_to_regmap()
rather than syscon_node_to_regmap().

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>