acpi: remove some legacy procfs interfaces

Hi,

This patchset is a first attempt to remove some of the deprecated procfs ACPI interfaces - in the final overall idea to remove /proc/acpi entirely. Based on the feature removal file, the CONFIG_ACPI_PROCFS_POWER and CONFIG_ACPI_PROC_EVENT options are dropped.

patch 1: removes CONFIG_ACPI_PROCFS_POWER
patch 2-5: removes CONFIG_ACPI_PROC_EVENT for acpi and respective drivers that use /proc/acpi/event.

The set applies ontop of Linus' latest.

Thanks,
Davidlohr