The RTC on S2MPS11 PMIC on Odroid XU3/XU4 family of boards can wakeup
the system from suspend to RAM.  Add a generic property for this.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210420164943.11152-10-krzysztof.kozlowski@canonical.com