ACPI: EC: Drop unused ident initializers from dmi_system_id tables

Drop the unused const string ident initializers from
the dmi_system_id tables to make the object size a bit smaller.

While at it also use proper named struct-member initializers for
the ec_dmi_table[].

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>