PCI: qcom: Select PCI Power Control Slot driver

Select the pwrctrl driver, which is utilized to manage the power supplies
of the devices connected to the standard PCI slots conforming to
specification like PCIe CEM. This ensures that the voltage rails of the
standard PCI slots on some platforms eg. X1E80100-QCP can be correctly
turned on/off if they are described in PCIe Root Port device tree node.

Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com>
Signed-off-by: Wenbin Yao <quic_wenbyao@quicinc.com>
[mani: reworded subject and description]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20250722091151.1423332-2-quic_wenbyao@quicinc.com