ACPI: Revert "ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c"

The commit 1e2d9cd and 7d7ee95 remove ACPI Proc Battery
directory and breaks some old userspace tools. This patch
is to revert 7d7ee95.

Fixes: 7d7ee958867a (ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c)
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ab686b3..c0160bb 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -47,6 +47,23 @@
 	depends on SUSPEND || HIBERNATION
 	default y
 
+config ACPI_PROCFS_POWER
+	bool "Deprecated power /proc/acpi directories"
+	depends on PROC_FS
+	help
+	  For backwards compatibility, this option allows
+          deprecated power /proc/acpi/ directories to exist, even when
+          they have been replaced by functions in /sys.
+          The deprecated directories (and their replacements) include:
+	  /proc/acpi/battery/* (/sys/class/power_supply/*)
+	  /proc/acpi/ac_adapter/* (sys/class/power_supply/*)
+	  This option has no effect on /proc/acpi/ directories
+	  and functions, which do not yet exist in /sys
+	  This option, together with the proc directories, will be
+	  deleted in 2.6.39.
+
+	  Say N to delete power /proc/acpi/ directories that have moved to /sys/
+
 config ACPI_EC_DEBUGFS
 	tristate "EC read/write access through /sys/kernel/debug/ec"
 	default n