PCI: Add builtin_pci_driver() to avoid registration boilerplate

In f309d4443130 ("platform_device: better support builtin boilerplate
avoidance"), we introduced the builtin_driver() macro.

Here we use that support and extend it to PCI driver registration, so where
a driver is clearly non-modular and builtin-only, we can register it in a
similar fashion.  Existing code that is clearly non-modular can be updated
with the simple mapping of

  module_pci_driver(...)  ---> builtin_pci_driver(...)

We've essentially cloned the former to make the latter, and taken out the
remove/module_exit parts since those never get used in a non-modular build
of the code.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

include/linux/pci.h

@@ -1192,6 +1192,17 @@ void pci_unregister_driver(struct pci_driver *dev);
 	module_driver(__pci_driver, pci_register_driver, \
 		       pci_unregister_driver)
 
+/**
+ * builtin_pci_driver() - Helper macro for registering a PCI driver
+ * @__pci_driver: pci_driver struct
+ *
+ * Helper macro for PCI drivers which do not do anything special in their
+ * init code. This eliminates a lot of boilerplate. Each driver may only
+ * use this macro once, and calling it replaces device_initcall(...)
+ */
+#define builtin_pci_driver(__pci_driver) \
+	builtin_driver(__pci_driver, pci_register_driver)
+
 struct pci_driver *pci_dev_driver(const struct pci_dev *dev);
 int pci_add_dynid(struct pci_driver *drv,
 		  unsigned int vendor, unsigned int device,