riscv: Add da9063_pmic and da9063_rtc to GENERIC and NOTES

[jrtc27]

Summary

This is the PMIC on SiFive's HiFive Unmatched; add it and the RTC child
device driver so we have a working RTC.

MFC after: 1 week

[imp]

I'd prefer if you called it da9063_pm instead of the named name da9063. It's generally preferable that device class names end in a letter.
Though maybe it's already that way in the tree

[jrtc27]

In D36201#821947, @imp wrote:

I'd prefer if you called it da9063_pm instead of the named name da9063. It's generally preferable that device class names end in a letter.
Though maybe it's already that way in the tree

D36199 is the revision for that; I can easily rename it to da9063_pmic.

[jrtc27]

Renamed da9063 to da9063_pmic