qcacmn: Initialize RX refill buffer pool size for SOFTUMAC arch
In the current code, RX refill buffer pool size is not initialized for
SOFTUMAC architectures, this was leading to a kernel BRK panic.
Initialize RX refill buffer pool size for SOFTUMAC architectures to fix
this.
Change-Id: I0424ba69b0d5f33386e931d4e6723fc8265e216c
CRs-Fixed: 3621417