wil6210: support regular scan on P2P_DEVICE interface

P2P search can only run on the social channel (channel 2).
When issuing a scan request on the P2P_DEVICE interface,
driver ignored the channels argument and always performed a P2P
search.
Fix this by checking the channels argument, if it is
not specified (meaning full scan) or if a non-social channel
was specified, perform a regular scan and not a P2P search.

Signed-off-by: Lior David <qca_liord@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>