iwl4965: reset firmware after rfkill off

commit 788f7a56fce1bcb2067b62b851a086fca48a0056 upstream.

Using rfkill switch can make firmware unstable, what cause various
Microcode errors and kernel warnings. Reseting firmware just after
rfkill off (radio on) helped with that.

Resolve:
https://bugzilla.redhat.com/show_bug.cgi?id=977053

Reported-and-tested-by: Justin Pearce <whitefox@guardianfox.net>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust filenames, context, naming]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>