ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write}

use_lock flag is used once for acpi_hw_register_read, and never for
acpi_hw_register_write. It will greatly simplify understanding of
locking if we just drop this use_lock altogether, and wrap the only call
to ..._read in lock/unlock.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>