[rdk-b][mt7986][wifi-hal][Add set STBC enable function]

[Description]
Add set STBC enable function. Use sed command to add or remove STBC flags im ht or vht capability.

[Release-log]
N/A

Change-Id: I35f91e69692d31c120e4d810f65411b11f1420f2
1 file changed