[ 2.919986] kernel: tegra_rtc c2a0000.rtc: registered as rtc1
[ 2.922877] kernel: tegra_rtc c2a0000.rtc: setting system clock to 1970-01-01T00:00:29 UTC (29)
[ 2.930866] kernel: tegra_rtc c2a0000.rtc: Tegra internal Real Time Clock
It seems you are using rtc1.
Please refer to the following thread to use rtc0 and check if it could help.
RTC can't hold time the after system rebooted in L4T 35.1 - #19 by ShaneCCC