ARM: dts: qcom: pm8226: add node for RTC

Add a node for PM8226's real time clock.

Signed-off-by: Jack Matthews <jm5112356@gmail.com>
Reviewed-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220209165742.652890-1-jm5112356@gmail.com