wil6210: add SPDX license identifiers

Change all files to add SPDX license identifiers and
remove license text.
This is only an administrative change, there is no change
in actual license or copyright for any file.

Signed-off-by: Lior David <liord@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

wil6210: add debugfs to show PMC ring content

PMC is a hardware debug mechanism which allows capturing real time
debug data and stream it to host memory. The driver allocates memory
buffers and set them inside PMC ring of descriptors.
Add pmcring debugfs that application can use to read the binary
content of descriptors inside the PMC ring (cat pmcring).

Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

wil6210: Add pmc debug mechanism memory management

Pmc is a hardware debug mechanism which allows capturing phy data,
packets, and internally generated events and messages synchronized
and time stamped by the hardware. It requires memory buffers
allocated by the driver in order to be used by hardware dma to
upstream real time debug data to host memory.
Driver will handle memory allocation and release, and fetching
the data from the memory to application layer via debug file
system. The configuration of pmc is handled entirely by the
application layer.

Signed-off-by: Vladimir Shulman <qca_shulmanv@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>