qcacld-3.0: Change prior conditions required for chainmask

Change the prior conditions required for configuring Rx Chainmask &
Tx Chainmask.
Below conditions should be met for setting chainmask:
1. Antenna sharing should be disabled.
2. If gEnable2x2 is 1 then enableBTChainSeparation must be 1
   else gEnable2x2 should be 0.
3. DBS should be disabled (gDualMacFeatureDisable = 1)
   or HW should be DBS 2x2 capable
4. set TX/RX chainmask 3 in ini (gSetTxChainmask1x1/gSetRxChainmask1x1)
5. HW should support TX/RX chainmask as 3

Change-Id: If83c55af47abb591cdf1b5d2e3981d80bc305bf2
CRs-Fixed: 2705520