asoc: Fix invalid size pointer access in routing driver

If data size is not greater than required size
while getting topology in routing driver, it leads
to invalid size pointer access. Add proper
size check to avoid this.

CRs-Fixed: 2384972
Change-Id: I8cd71a4ae866aca57c6d711cfd07e20c5edee3ae
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>