iwlwifi: change iwl->priv iwl_priv * type in iwl-YYY-io.h

This patch makes all variables of type struct iwl_priv to be named priv
This is needed for smooth change of debug printing mechanism

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Ester Kummer <ester.kummer@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>