ACPI: probe ECDT before loading AML tables regardless of module-level code flag

It was discovered that AML tables were loaded before or after the
ECDT depending on acpi_gbl_execute_tables_as_methods. According to
the ACPI spec, the ECDT should be loaded before the namespace is
populated by loading AML tables (DSDT and SSDT). Since the ECDT
should be loaded early in the boot process, this change moves the
ECDT probing to acpi_early_init.

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