wcn36xx: initialize device defaults on start

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: Bob Copeland <bob@cozybit.com>
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Changes since v1:
  - remove some possibly inapplicable or unnecessary settings
wcn36xx: let device generate qos seq numbers

wcn36xx currently sends an incorrect sequence number into the BA session
setup firmware command: it should be saving or updating the ssn in the
TX_START ampdu_action callback instead of waiting until TX_OPERATIONAL.
However, we can sidestep the issue by letting the hardware generate the
sequence numbers for QoS frames, as is done in prima, so do that.

Signed-off-by: Bob Copeland <bob@cozybit.com>

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Changes since v1:
  - use symbolic constant instead of plain 2 (Chun-Yeow Yeoh)
wcn36xx: use !! when assigning int as a boolean

bd->tx_comp is a single bit in a bitfield, so assigning
"info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS" only happens
to work because TX_STATUS is defined to BIT(0); if it were
any other bit this assignment would fail.

Signed-off-by: Bob Copeland <bob@cozybit.com>
Merge pull request #137 from bcopeland/master

tx ampdu fixes