rsi: Update in tx command frame radio capabilities

Radio capabilities frame is updated to use common descriptor
structure. Also, few changes to this frame is done like hardware
queues are increase to 12 from 8, default channel number is included.

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