arm64: dts: qcom: qcs6490-rb3gen2: Add TC9563 PCIe switch node

arm64: dts: qcom: qcs6490-rb3gen2: Add TC9563 PCIe switch node

Add a node for the TC9563 PCIe switch, which has three downstream ports.
Two embedded Ethernet devices are present on one of the downstream ports.
As all these ports are present in the node represent the downstream
ports and embedded endpoints.

Power to the TC9563 is supplied through two LDO regulators, controlled by
two GPIOs, which are added as fixed regulators. Configure the TC9563
through I2C.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260105-tc9563-v1-1-642fd1fe7893@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>