ACPI: Remove CONFIG_ACPI_PROCFS_POWER and cm_sbsc.c

There is no user of cm_sbs.c and CONFIG_ACPI_PROCFS_POWER. So remove
them. Prepare for removing /proc/acpi

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>