arm64: dts: qcom: add support for pixel 3a xl with the tianma panel

arm64: dts: qcom: add support for pixel 3a xl with the tianma panel

The Pixel 3a XL has variants with either a Samsung Display Controller (SDC)
panel or a Tianma panel. Add the device tree for the variant with the
Tianma panel.

Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Assisted-by: "Claude Code Review Bot":claude-opus-4-6
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260513172549.1345-3-mailingradian@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>