Add user configurable transport mode

This commit gives the user opportunity to select the transport mode
to get the csi data. The command to add the transport mode as below
Example: CSI start 900 1
Here 900 represents the CSI duration (in sec) to capture CSI data.
Below is the transport mode corresponding to user
input:

0 - QCA_WLAN_VENDOR_CFR_DATA_RELAY_FS
1 - QCA_WLAN_VENDOR_CFR_DATA_NETLINK_EVENTS

Change-Id: Ifcbb00ba8c284f685b1c01b6f09f0552e5417e3d
CRs-Fixed: 2974322