platform/x86: think-lmi: use correct possible_values delimiters

platform/x86: think-lmi: use correct possible_values delimiters

firmware-attributes class requires that possible values are delimited
using ';' but the Lenovo firmware uses ',' instead.
Parse string and replace where appropriate.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms")
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20230320003221.561750-2-mpearson-lenovo@squebb.ca
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>