ring_buffer: update Kconfig help text

Make it more informative and useful.

Buffer sizes that are a power of 2 didn't provide any advantage since
commit 099850e916ad ("ring_buffer: the great simplification").

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>

lib/utils/Kconfig

diff --git a/lib/utils/Kconfig b/lib/utils/Kconfig
index 1e3c210..4fb6a32 100644
--- a/lib/utils/Kconfig
+++ b/lib/utils/Kconfig
@@ -12,9 +12,9 @@
 config RING_BUFFER
 	bool "Ring buffers"
 	help
-	  Enable usage of ring buffers. This is similar to kernel FIFOs but ring
-	  buffers manage their own buffer memory and can store arbitrary data.
-	  For optimal performance, use buffer sizes that are a power of 2.
+	  Provide highly efficient ring buffer management for arbitrary data.
+	  Some facilities such as kernel pipes are built on top of this.
+	  May be used directly e.g. when the pipe overhead is unnecessary.
 
 config NOTIFY
 	bool "Asynchronous Notifications"