driver core: Remove unused platform_notify, platform_notify_remove

The "platform_notify" and "platform_notify_remove" hooks have been unused
since 00ba935 ("ARM: ixp4xx: Drop custom DMA coherency and bouncing").

Remove "platform_notify" and "platform_notify_remove".  No functional
change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240325221409.1457036-1-helgaas@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: bjorn-helgaas

drivers/base/core.c

@@ -2331,8 +2331,6 @@ static void fw_devlink_link_device(struct device *dev)
 
 /* Device links support end. */
 
-int (*platform_notify)(struct device *dev) = NULL;
-int (*platform_notify_remove)(struct device *dev) = NULL;
 static struct kobject *dev_kobj;
 
 /* /sys/dev/char */
@@ -2380,16 +2378,10 @@ static void device_platform_notify(struct device *dev)
 	acpi_device_notify(dev);
 
 	software_node_notify(dev);
-
-	if (platform_notify)
-		platform_notify(dev);
 }
 
 static void device_platform_notify_remove(struct device *dev)
 {
-	if (platform_notify_remove)
-		platform_notify_remove(dev);
-
 	software_node_notify_remove(dev);
 
 	acpi_device_notify_remove(dev);

include/linux/device.h

@@ -1206,17 +1206,6 @@ int __must_check devm_device_add_groups(struct device *dev,
 int __must_check devm_device_add_group(struct device *dev,
 				       const struct attribute_group *grp);
 
-/*
- * Platform "fixup" functions - allow the platform to have their say
- * about devices and actions that the general device layer doesn't
- * know about.
- */
-/* Notify platform of device discovery */
-extern int (*platform_notify)(struct device *dev);
-
-extern int (*platform_notify_remove)(struct device *dev);
-
-
 /*
  * get_device - atomically increment the reference count for the device.
  *