devlink: make devlink_flash_overwrite enum named one

Since this enum is going to be used in generated userspace file, name it
properly.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231021112711.660606-7-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/uapi/linux/devlink.h

@@ -265,7 +265,7 @@ enum {
  * Documentation/networking/devlink/devlink-flash.rst
  *
  */
-enum {
+enum devlink_flash_overwrite {
 	DEVLINK_FLASH_OVERWRITE_SETTINGS_BIT,
 	DEVLINK_FLASH_OVERWRITE_IDENTIFIERS_BIT,