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

wmi_unified_param.h

@@ -5775,6 +5775,7 @@ typedef enum {
 	wmi_pdev_param_soft_tx_chain_mask,
 	wmi_pdev_param_cck_tx_enable,
 	wmi_pdev_param_esp_indication_period,
+	wmi_pdev_param_antenna_gain_half_db,
 	wmi_pdev_param_max,
 } wmi_conv_pdev_params_id;