Add some help texts to recently-introduced kconfig items

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (edited MACINTOSH_DRIVERS per Geert Uytterhoeven's remark)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index f952493..f16a46e 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -1228,6 +1228,11 @@
 	bool "Instrumentation Support"
 	depends on EXPERIMENTAL
 	default y
+	---help---
+	  Say Y here to get to see options related to performance measurement,
+	  debugging, and testing. This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and disabled.
 
 if INSTRUMENTATION