qcacmn: Add support for twice antenna gain param

Existing antenna gain command does not take odd antenna gain value that is
gains are not supported in steps of 0.5db. antenna_gain_half_db pdev
param provides this support. Added WMI and CDP changes to configure/read
this data.
CRs-Fixed: 2024854
Change-Id: I47da9eed74a1a0180cefb4c3f47bc4340da1bdfd
1 file changed