Add compatible for AM62x SoC based Low Power Starter Kit board[1]

[1] https://www.ti.com/tool/SK-AM62-LPSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230321-am62-lp-sk-v2-1-0a56e1694804@ti.comSigned-off-by: Nishanth Menon <nm@ti.com>