soc: samsung: exynos-chipid: initialize later - with arch_initcall

The Exynos ChipID driver on Exynos SoCs has only informational
purpose - to expose the SoC device in sysfs.  No other drivers
depend on it so there is really no benefit of initializing it early.

Instead, initialize everything with arch_initcall which:
1. Allows to use dev_info() as the SoC bus is present (since
   core_initcall),
2. Could speed things up because of execution in a SMP environment
   (after bringing up secondary CPUs, unlike early_initcall),
3. Reduces the amount of work to be done early, when the kernel has to
   bring up critical devices.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201202195955.128633-2-krzk@kernel.org