qcacmn: Use fix length for RADIOTAP_HEADER instead of arbitary length

Use fixed max length for RADIOTAP_HEADER instead of arbitary
length. Increase the RADIOTAP_HEADER length when we add more radiotap
elements

Change-Id: I0d290b0def8408029ee787999faa4498b75b212f
CRs-Fixed: 2217245
1 file changed