ARM: dts: exynos: Silence SATA PHY warning in Exynos5250

ARM: dts: exynos: Silence SATA PHY warning in Exynos5250

The SATA PHY in Exynos5250 SoCs has two interfaces and two device nodes:
1. sata-phy@12170000
2. i2c-9/i2c@38

The first node represents the actual SATA PHY device with phy-cells.

The second represents an additional I2C interface, needed by the driver
to communicate with the SATA PHY device.  It is not a PHY-provider in
the terms of dtschema so rename it to silence dtbs_check warning:

  arch/arm/boot/dts/exynos5250-arndale.dt.yaml: sata-phy@38: '#phy-cells' is a required property
    From schema: lib/python3.6/site-packages/dtschema/schemas/phy/phy-provider.yaml

This second device node is also a property of SoC, not a board so move
it there.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200902155733.20271-2-krzk@kernel.org