qcacmn: Fix minor pn_size init and index check

1. In hal reo setup initialize pn_size to avoid uninitialization
in default case.
2. In hal validate shadow register function, fix the check
for index as shadow_config array can take 0 to 35 as index values.

Change-Id: I8b729dc70053e333ef659ba38fb0c2f66cd8b35a
CRs-fixed: 2208799
2 files changed