ACPI: delete CONFIG_ACPI_PROCFS_POWER and power procfs I/F in 2.6.39

ACPI: delete CONFIG_ACPI_PROCFS_POWER and power procfs I/F in 2.6.39

sysfs I/F for ACPI power devices, including AC and Battery,
has been working in upstream kenrel since 2.6.24, Sep 2007.
In 2.6.37, we made the sysfs I/F always built in and this option
disabled by default.
Now, we plan to remove this option and the ACPI power procfs
interface in 2.6.39.

First, update the feature-removal-schedule to announce this change.
Second, add runtime warnings in ACPI AC/Battery/SBS driver, so that
users will notice this change even if "make oldconfig" is used.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>