qcacmn: Set the Tx completion ring size to appropriate value

Size the completion ring using following 2 parameters
 - NAPI schedule latency (assuming 1 netdev, gmac, competing for CPU) = 20ms
								 (2 jiffies)
 - Worst case PPS requirement = 400K PPS
    Ring size = 20 * 400 = 8000

Change-Id: Iaac0b61f50b52a4e824c3c8ef5d980adf455854c
CRs-Fixed: 2068155
3 files changed