reverse CONFIG_ACPI_PROC_EVENT default

Sigh.  Again an ACPI assault on the Thinkpad's Fn+F4 to suspend to RAM.
The default and text for CONFIG_THINKPAD_ACPI_INPUT_ENABLED were fixed
in -rc3, but now commit 14e04fb34ffa82ee61ae69f98d8fca12d2e8e31c ("ACPI:
Schedule /proc/acpi/event for removal") introduces the ACPI_PROC_EVENT
config entry, and defaults it to 'n' to disable it again.

Change default to y, and add comment to make it clearer that n is for
future distros.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 5742594..4875f01 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -71,6 +71,7 @@
 config ACPI_PROC_EVENT
 	bool "Deprecated /proc/acpi/event support"
 	depends on PROC_FS
+	default y
 	---help---
 	  A user-space daemon, acpi, typically read /proc/acpi/event
 	  and handled all ACPI sub-system generated events.
@@ -78,10 +79,13 @@
 	  These events are now delivered to user-space via
 	  either the input layer, or as netlink events.
 
-	  This build option enables the old code for for legacy
+	  This build option enables the old code for legacy
 	  user-space implementation.  After some time, this will
 	  be moved under CONFIG_ACPI_PROCFS, and then deleted.
 
+	  Say Y here to retain the old behaviour.  Say N if your
+	  user-space is newer than kernel 2.6.23 (September 2007).
+
 config ACPI_AC
 	tristate "AC Adapter"
 	depends on X86