interconnect: Remove unused module exit code from core

The interconnect core is currently always built in:

 menuconfig INTERCONNECT
	bool "On-Chip Interconnect management support"

So remove the module_exit function and symbolically rename module_init
to device_initcall to drive home the point.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1572546532-19248-3-git-send-email-jcrouse@codeaurora.orgSigned-off-by: Georgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/core.c

@@ -944,12 +944,7 @@ static int __init icc_init(void)
 	return 0;
 }
 
-static void __exit icc_exit(void)
-{
-	debugfs_remove_recursive(icc_debugfs_dir);
-}
-module_init(icc_init);
-module_exit(icc_exit);
+device_initcall(icc_init);
 
 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
 MODULE_DESCRIPTION("Interconnect Driver Core");