iwlwifi-2.6: RX status translation to old scheme

This patch adds translation for the RX status of an incoming packet.
The incoming status has to be translated to the old scheme in order to know
if the decryption has been done, MIC failure has occured, TTAK is valid etc...
This translation is mandatory for all RX packets when using 5300 and for
all HT packets using 4965.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>