Add SC8280XP to the DT schema.

Link: https://lore.kernel.org/r/20220711101441.4896-1-johan+linaro@kernel.orgReviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>