rsi: data packet descriptor enhancements

This patch covers some enhancements in data packet descriptor
preparation especially for EAPOL, multicast/broadcast packets.

Signed-off-by: Pavani Muthyala <pavani.muthyala@redpinesignals.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>