Set up default configuration for the device when we call start.
The defaults come from dumps from the prima driver for the same
hardware.

This fixes transmit A-MPDU; previously only one MPDU would be
sent per A-MPDU due to missing MAX_MPDUS_IN_AMPDU setting.
Signed-off-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>