PCI/pwrctrl: slot: Rename private struct and pointers for consistency

PCI/pwrctrl: slot: Rename private struct and pointers for consistency

Previously the pwrseq, tc9563, and slot pwrctrl drivers used different
naming conventions for their private data structs and pointers to them,
which makes patches hard to read.

Rename structs, variables, and functions to reduce boiler-plate and start
with "slot":

  struct pci_pwrctrl_slot_data      -> struct slot_pwrctrl
  struct pci_pwrctrl ctx            -> struct pci_pwrctrl pwrctrl
  pci_pwrctrl_slot_probe()          -> slot_pwrctrl_probe()
  pci_pwrctrl_slot_of_match[]       -> slot_pwrctrl_of_match[]
  pci_pwrctrl_slot_driver           -> slot_pwrctrl_driver
  devm_pci_pwrctrl_slot_power_off() -> devm_slot_pwrctrl_power_off()

No functional change intended.

[bhelgaas: move "slot" to beginning, also rename functions, etc]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-2-9d26da3ce903@oss.qualcomm.com