platform/x86: think-lmi: Use ACPI object when extracting strings

Move the ACPI buffer handling out of tlmi_extract_output_string()
and instead pass the unpacked ACPI object to prepare for future
changes.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20250216193251.866125-3-W_Armin@gmx.de


Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>