iwlwifi: pcie: align licensing to dual GPL/BSD

These files have a long history of code changes, but analysing
the remaining code leads to having only a few changes that are
not already owned by Intel, notably from
 - Andy Lutomirski <luto@amacapital.net>
 - Joonwoo Park <joonwpark81@gmail.com>
 - Kirtika Ruchandani <kirtika@chromium.org>
 - Rajat Jain <rajatja@google.com>
 - Stanislaw Gruszka <sgruszka@redhat.com>
remaining in the code today.

Note that
 - I myself was working for Intel and for any possibly code
   that might be before my employment there give permission
 - Wizery employees were working for Intel

More specifically, we identified the following commits that
(partially may) remain today:

25c03d8e Joonwoo Park <joonwpark81@gmail.com>      ("iwlwifi: do not schedule tasklet when rcv unused irq")
f36d04ab Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: use dma_alloc_coherent")
387f3381 Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: fix dma mappings and skbs leak")
2624e96c Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: fix possible data overwrite in hcmd callback")
bfe4b80e Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: always check if got h/w access before write")
d536c32b Andy Lutomirski <luto@amacapital.net>     ("iwlwifi: pcie: log when waking the NIC for hcmd submission fails")
a6d24fad Rajat Jain <rajatja@google.com>           ("iwlwifi: pcie: dump registers when HW becomes inaccessible")
fb12777a Kirtika Ruchandani <kirtika@chromium.org> ("iwlwifi: Add more call-sites for pcie reg dumper")
3a73a300 Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: cleanup/fix memory barriers")
aa5affba Stanislaw Gruszka <sgruszka@redhat.com>   ("iwlwifi: dump stack when fail to gain access to the device")

Align the licenses with their permission to clean up and to
make it all identical.

CC: Joonwoo Park <joonwpark81@gmail.com>
CC: Stanislaw Gruszka <sgruszka@redhat.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Rajat Jain <rajatja@google.com>
CC: Kirtika Ruchandani <kirtika@chromium.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Kirtika Ruchandani <kirtika@chromium.org>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Joonwoo Park <joonwpark81@gmail.com>
Acked-by: Rajat Jain <rajatja@google.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>