arm64: dts: qcom: x1e80100: describe uefi rtc offset

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: b53c2c23d3c2 ("arm64: dts: qcom: x1e80100: enable rtc")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250423075143.11157-5-johan+linaro@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>