arm64: dts: qcom: sc8280xp-x13s: describe uefi rtc offset

On many Qualcomm platforms the PMIC RTC control and time registers are
read-only so that the RTC time can not be updated. Instead an offset
needs be stored in some machine-specific non-volatile memory, which a
driver can take into account.

On platforms where the offset is stored in a Qualcomm specific UEFI
variable the variables are also accessed in a non-standard way, which
means that the OS cannot assume that the variable service is available
by the time the RTC driver probes.

Use the new 'qcom,uefi-rtc-info' property to indicate that the offset is
stored in a UEFI variable so that the OS can determine whether to wait
for it to become available.

Fixes: 4098036 ("arm64: dts: qcom: sc8280xp-x13s: switch to uefi rtc offset")
Signed-off-by: Johan Hovold <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

Author: jhovold

arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts

@@ -1090,6 +1090,8 @@
 };
 
 &pmk8280_rtc {
+	qcom,uefi-rtc-info;
+
 	status = "okay";
 };