Now, there are only two functions to send a host command:
* send_cmd that receives a iwl_host_cmd
* send_cmd_pdu that builds the iwl_host_cmd itself and received flags

The flags CMD_ASYNC / CMD_SYNC / CMD_WANT_SKB are not changed by the API
functions.

Kill the unused flags CMD_SIZE_NORMAL / CMD_NO_SKB on the way.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>