linux-imx

ACPI: fix obsolete comment in custom_method.c

The comment describing the contents of the custom_method.c file is
obsolete, so update it.

[rjw: Subject and changelog]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>