wlan: Fix integer truncation in convert_wsc_opaque

Propagation from qcacld-3.0 to prima

In the function convert_wsc_opaque, driver does copy of the
new parameters present in the additional IEs of the upstream
assoc request frame. While copy of the IE length pOld->length to
curAddIELen, possible integer truncation could occur, as the
curAddIELen is of the type uint8_t whereas pOld->length is of
type uint16_t.

Change the data type of curAddIELen to uint16_t. Make changes in
convert_p2p_opaque and convert_wfd_opaque as well.

Change-Id: Ic26660fca4a02a265bfc9553b066c7ee42f1d1f4
CRs-Fixed: 2517889