arm64: dts: qcom: sa8155p-adp: enable the GNSS high-speed UART

Enable the high-speed UART port that's connected to the GNSS controller
on the board.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230309143551.200694-3-brgl@bgdev.pl