The vendor driver code suggests that CR47 patching happens on every channel
change for every RF (depending on bit 8 in POD).

Due to a bug in their driver (upper bits of RF_Mode get zeroed out, then
are examined for 1s when setting some other flags), this isn't actually
what happens, and their generic CCK patching routine never takes effect.

Some of their RF configurations do include explicit (duplicated) code
for CR47 patching though. This patch makes zd1211rw match that
behaviour.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>