platform/x86/siemens: Kconfig: adjust help text

There was a copy and paste mistake where the module name was not
correct.

Fixes: 917f5434 ("platform/x86: simatic-ipc: add CMOS battery monitoring")
Signed-off-by: Henning Schild <henning.schild@siemens.com>
Link: https://lore.kernel.org/r/20230725093113.9739-3-henning.schild@siemens.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>