feat: bump overlays rockchip & raspberrypi

[smira]

• https://github.com/siderolabs/sbc-raspberrypi/releases/tag/v0.1.0-beta.1
• https://github.com/siderolabs/sbc-rockchip/releases/tag/v0.1.0-beta.2

[frezbo]

oh release notes needs an update, and README too, there was a new sbc added

[smira]

/m