riscv: dts: spacemit: add Ethernet and PDMA to OrangePi RV2

riscv: dts: spacemit: add Ethernet and PDMA to OrangePi RV2

The OrangePi RV2 board ships two RGMII ethernet ports.
Each has an external Motorcomm YT8531C PHY attached, the PHY uses GPIO
for reset pin control.

Enable PDMA for the SpacemiT K1-based SoC in the OrangePi RV2 board.

Signed-off-by: Michael Opdenacker <michael.opdenacker@rootcommit.com>
Reviewed-by: Yixun Lan <dlan@gentoo.org>
Link: https://lore.kernel.org/r/20251022201807.1474789-2-michael.opdenacker@rootcommit.com
Signed-off-by: Yixun Lan <dlan@gentoo.org>