wil6210: support sniffer in EDMA mode

Sniffer in EDMA mode is required for supporting sniffer for
CB2 traffic.
Sniffer mode is supported only with extended RX status messages,
hence use_compressed_rx_status is cleared in sniffer mode.
The sniffer info is configured in a new section added to
WMI_CFG_DEF_RX_OFFLOAD command.
The radiotap header is added to the RX data and its size is taken into
account when allocating the RX SKBs.

Change-Id: I36fa4502eab2880ae39cf0a0697eb5793cb45335
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Ahmad Masri <amasri@codeaurora.org>
Signed-off-by: Alexei Avshalom Lazar <ailizaro@codeaurora.org>