arm64: dts: qcom: sa8775p-ride-r3: add new board file

Revision 3 of the sa8775p-ride board uses a different PHY for the two
ethernet ports and supports 2.5G speed. Create a new file for the board
reflecting the changes.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240627114212.25400-4-brgl@bgdev.pl


Signed-off-by: Bjorn Andersson <andersson@kernel.org>