Add support for following boards:

- Xperia X Performance (dora)
- Xperia XZ (kagura)
- Xperia XZs (keyaki)

They are all based on the SONY Tone platform and feature largely similar hardware
with the most obvious differences being lack of USB-C and ToF sensor on Dora and
different camera sensor on Keyaki.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Link: https://lore.kernel.org/r/20210608202143.247427-4-konrad.dybcio@somainline.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>