arm64: dts: qcom: Add The Fairphone (Gen. 6)

arm64: dts: qcom: Add The Fairphone (Gen. 6)

Add a devicetree for The Fairphone (Gen. 6) smartphone, which is based
on the Milos/SM7635 SoC.

Supported functionality as of this initial submission:
* Debug UART
* Regulators (PM7550, PM8550VS, PMR735B, PM8008)
* Remoteprocs (ADSP, CDSP, MPSS, WPSS)
* Power Button, Volume Keys, Switch
* PMIC-GLINK (Charger, Fuel gauge, USB-C mode switching)
* Camera flash/torch LED
* SD card
* USB

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251210-sm7635-fp6-initial-v4-9-b05fddd8b45c@fairphone.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>