alarmtimer: no way to choose the RTC on boards with two wakeup RTCs

[Igor Velkov]

Hi,

alarmtimer_rtc_add_device() binds to the first registered RTC that has
RTC_FEATURE_ALARM and a wakeup-capable parent, and keeps it. With two such
RTCs the choice follows probe order: ODROID-N2/N2+ (pcf8563 and meson-vrtc),
ODROID-HC4 with its RTC add-on, and 11 rockchip boards in v7.3 DT with a
hym8563/pcf8563 next to an RK808-family PMIC RTC. On HC4 meson-vrtc wins.

I found no DT property, command-line option or sysfs knob to make the choice
explicit. Is there an intended way? If not, where would such a setting
belong, and under what name?

Igor