Revert "ACPICA: executer/exsystem: Warn about sleeps greater than 10 ms"

Commit 6eaf0877 ("ACPICA: executer/exsystem: Warn about sleeps
greater than 10 ms") made acpi_ex_system_do_sleep() log a warning for
sleep times greater than 10 ms, but such sleep times are used in
power management AML because of the PCI specification requirements.

This results with logging warnings that cannot really be acted on in
any useful way which is annoying and these warnings show up in the logs
on many production systems, so revert commit 6eaf0877.

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