PCI/PME: Restore pcie_pme_driver.remove

In addition to making PME non-modular, d7def204 ("PCI/PME: Make
explicitly non-modular") removed the pcie_pme_driver .remove() method,
pcie_pme_remove().

pcie_pme_remove() freed the PME IRQ that was requested in pci_pme_probe().
The fact that we don't free the IRQ after d7def204 causes the following
crash when removing a PCIe port device via /sys:

  ------------[ cut here ]------------
  kernel BUG at drivers/pci/msi.c:370!
  invalid opcode: 0000 [#1] SMP
  Modules linked in:
  CPU: 1 PID: 14509 Comm: sh Tainted: G    W  4.8.0-rc1-yh-00012-gd29438d6
  RIP: 0010:[<ffffffff9758bbf5>]  free_msi_irqs+0x65/0x190
  ...
  Call Trace:
   [<ffffffff9758cda4>] pci_disable_msi+0x34/0x40
   [<ffffffff97583817>] cleanup_service_irqs+0x27/0x30
   [<ffffffff97583e9a>] pcie_port_device_remove+0x2a/0x40
   [<ffffffff97584250>] pcie_portdrv_remove+0x40/0x50
   [<ffffffff97576d7b>] pci_device_remove+0x4b/0xc0
   [<ffffffff9785ebe6>] __device_release_driver+0xb6/0x150
   [<ffffffff9785eca5>] device_release_driver+0x25/0x40
   [<ffffffff975702e4>] pci_stop_bus_device+0x74/0xa0
   [<ffffffff975704ea>] pci_stop_and_remove_bus_device_locked+0x1a/0x30
   [<ffffffff97578810>] remove_store+0x50/0x70
   [<ffffffff9785a378>] dev_attr_store+0x18/0x30
   [<ffffffff97260b64>] sysfs_kf_write+0x44/0x60
   [<ffffffff9725feae>] kernfs_fop_write+0x10e/0x190
   [<ffffffff971e13f8>] __vfs_write+0x28/0x110
   [<ffffffff970b0fa4>] ? percpu_down_read+0x44/0x80
   [<ffffffff971e53a7>] ? __sb_start_write+0xa7/0xe0
   [<ffffffff971e53a7>] ? __sb_start_write+0xa7/0xe0
   [<ffffffff971e1f04>] vfs_write+0xc4/0x180
   [<ffffffff971e3089>] SyS_write+0x49/0xa0
   [<ffffffff97001a46>] do_syscall_64+0xa6/0x1b0
   [<ffffffff9819201e>] entry_SYSCALL64_slow_path+0x25/0x25
  ...
   RIP  [<ffffffff9758bbf5>] free_msi_irqs+0x65/0x190
   RSP <ffff89ad3085bc48>
  ---[ end trace f4505e1dac5b95d3 ]---
  Segmentation fault

Restore pcie_pme_remove().

[bhelgaas: changelog]
Fixes: d7def204 ("PCI/PME: Make explicitly non-modular")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org	# v4.9+

drivers/pci/pcie/pme.c

@@ -433,6 +433,17 @@ static int pcie_pme_resume(struct pcie_device *srv)
 	return 0;
 }
 
+/**
+ * pcie_pme_remove - Prepare PCIe PME service device for removal.
+ * @srv - PCIe service device to remove.
+ */
+static void pcie_pme_remove(struct pcie_device *srv)
+{
+	pcie_pme_suspend(srv);
+	free_irq(srv->irq, srv);
+	kfree(get_service_data(srv));
+}
+
 static struct pcie_port_service_driver pcie_pme_driver = {
 	.name		= "pcie_pme",
 	.port_type	= PCI_EXP_TYPE_ROOT_PORT,
@@ -441,6 +452,7 @@ static struct pcie_port_service_driver pcie_pme_driver = {
 	.probe		= pcie_pme_probe,
 	.suspend	= pcie_pme_suspend,
 	.resume		= pcie_pme_resume,
+	.remove		= pcie_pme_remove,
 };
 
 /**