tracing: Fix sysview for soc families not subdivided into series

Fixes the systemview tracing backend for soc families, such as max32,
that don't subdivide into soc series and therefore don't define
CONFIG_SOC_SERIES. Use CONFIG_SOC_FAMILY instead in the system
description since it should always be defined.

Signed-off-by: Maureen Helm <maureen.helm@analog.com>