arm64: dts: qcom: x1e80100: 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: b53c2c2 ("arm64: dts: qcom: x1e80100: enable rtc")
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/x1e80100-pmics.dtsi

@@ -224,6 +224,7 @@
 			reg-names = "rtc", "alarm";
 			interrupts = <0x0 0x62 0x1 IRQ_TYPE_EDGE_RISING>;
 			qcom,no-alarm; /* alarm owned by ADSP */
+			qcom,uefi-rtc-info;
 		};
 
 		pmk8550_sdam_2: nvram@7100 {