[iwn] scan fixes!

[Adrian Chadd]

I've tested this now on the Intel 5100 and the Centrino-N 2200
(specifically to keep eadler@ happy!)

It turns out that yes, the 2200 works fine, and it also exposes the
firmware TLV "flags" field, which includes a bunch of things:

iwn1: iwn_read_firmware_tlv: feature: 0x0000000b

So that is 1011 - P2P (bit 3), NEWSCAN (bit 1), and PAN (bit 0.)

The NEWSCAN bit changes the behaviour of the scan command a little.
Seems to behave fine on both the 5100 (no flags TLV, so no NEWSCAN)
and 2200 (NEWSCAN.)



-adrian