soc: samsung: exynos-chipid: avoid soc_device_to_device()

soc: samsung: exynos-chipid: avoid soc_device_to_device()

soc_device_to_device() seems to be discouraged [1] so remove it in favor
of printing info message with platform device.  This will only change
the prefix in the info message from "soc soc0: " to "exynos-chipid
10000000.chipid:".

[1] https://lore.kernel.org/lkml/20191111052741.GB3176397@kroah.com/

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
Tested-by: Sylwester Nawrocki <snawrocki@kernel.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20210919093114.35987-2-krzysztof.kozlowski@canonical.com