iwlwifi: trigger scan synchronously

Scan requesting doesn't need to be asynchronous
since all code paths leading up to it can sleep.
Make the scan request a new util operation that
is hw-specific (to account for 3945 vs. agn)
and call it right in place.

This patch moves a lot of code into iwlagn as
it need not be in iwlcore.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-hcmd.c b/drivers/net/wireless/iwlwifi/iwl-agn-hcmd.c
index 28bc8f8..231d0e6 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-hcmd.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-hcmd.c
@@ -271,4 +271,5 @@
 	.chain_noise_reset = iwlagn_chain_noise_reset,
 	.rts_tx_cmd_flag = iwlagn_rts_tx_cmd_flag,
 	.calc_rssi = iwlagn_calc_rssi,
+	.request_scan = iwlagn_request_scan,
 };