ACPI: Kconfig: fold /proc/acpi/sleep under CONFIG_ACPI_PROCFS

/proc/acpi/sleep has had its own "default n" option,
ACPI_SLEEP_PROC_SLEEP, for many months.
Time to delete ACPI_SLEEP_PROC_SLEEP.

Users that still need /proc/acpi/sleep can still get it
along with the other deprecated /proc/acpi files
by enabling CONFIG_ACPI_PROCFS.

Also delete ACPI_SLEEP_PROC_FS, which was an umbrella
for /proc/acpi/sleep, wakeup, alarm, because it was
effectively just a synonym for ACPI_SLEEP.

Signed-off-by: Len Brown <len.brown@intel.com>