ACPICA: Debugger: Fix runtime stub issues of ACPI_DEBUGGER_EXEC using different stub mechanism

ACPICA commit 11522d6b894054fc4d62dd4f9863ec151296b386

The ACPI_DEBUGGER_EXEC is a problem now when the debugger code is compiled
but runtime disabled. They actually will get executed in this situation.
Although such executions are harmless if we can correctly make
acpi_db_single_step() a runtime stub, users may still do not want to see the
debugger print messages logged into OSPMs' kernel logs when a debugger
driver is not loaded to enable the debugger during runtime.

This patch fixes this issue by introducing new stub mechanism instead of
ACPI_DEBUGGER_EXEC. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/11522d6b
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>