In the future, multiple SMM calling backends will exist,
with each backend being required to initialize its data.
Introduce a helper function for this so the code necessary
to initialize dell_smm_data is not duplicated between
different backends.

Tested-by: <serverror@serverror.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231123004820.50635-7-W_Armin@gmx.deSigned-off-by: Guenter Roeck <linux@roeck-us.net>