block: remove CONFIG_EXPERIMENTAL

This config item has not carried much meaning for a while now and is
almost always enabled by default. As agreed during the Linux kernel
summit, remove it.

CC: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/Kconfig

@@ -89,7 +89,7 @@ config BLK_DEV_INTEGRITY
 
 config BLK_DEV_THROTTLING
 	bool "Block layer bio throttling support"
-	depends on BLK_CGROUP=y && EXPERIMENTAL
+	depends on BLK_CGROUP=y
 	default n
 	---help---
 	Block layer bio throttling support. It can be used to limit