iwlwifi: mvm: clear up iwl_mvm_notify_rx_queue() argument type

iwlwifi: mvm: clear up iwl_mvm_notify_rx_queue() argument type

The argument type to iwl_mvm_notify_rx_queue() is currently just
a u8 *, but that's misleading because we actually need the inner
data to be of type struct iwl_mvm_internal_rxq_notif, because we
interpret it when we get it back from the device (to check the
sync bool and possibly the cookie.)

Therefore, clear up any potential confusion and require that the
data passed is of type struct iwl_mvm_internal_rxq_notif *.

Also, while at it, rename the "count" to "notif_size" as "count"
doesn't really clearly say what it's counting.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.d28e14682bdc.I9ac366aa97db045be4daa4ba263267a3ac6a6a2f@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>