qcacld-3.0: Revert RSSI vendor attr api to nla_put_u32

The reverts commit 35160f2ec779 ("qcacld-3.0: Signal value on
p2p-go mode error").
Since vendor command attribute already submit to open source,
we can't change the QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_MGMT
and QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_DATA and
QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_ACK to signed 32 bit.
So, revert the api of nla_put_s32 to nla_put_u32.

Change-Id: I70514c4edfd12a401a3549839075b657ed5e6a5a
CRs-Fixed: 3566162

core/hdd/src/wlan_hdd_stats.c

@@ -1123,13 +1123,13 @@ static bool put_wifi_iface_stats(struct wifi_interface_stats *if_stat,
 	    nla_put_u32(vendor_event,
 			QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_MGMT_ACTION_TX,
 			link_stats->mgmt_action_tx) ||
-	    nla_put_s32(vendor_event,
+	    nla_put_u32(vendor_event,
 			QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_MGMT,
 			link_stats->rssi_mgmt) ||
-	    nla_put_s32(vendor_event,
+	    nla_put_u32(vendor_event,
 			QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_DATA,
 			link_stats->rssi_data) ||
-	    nla_put_s32(vendor_event,
+	    nla_put_u32(vendor_event,
 			QCA_WLAN_VENDOR_ATTR_LL_STATS_IFACE_RSSI_ACK,
 			link_stats->rssi_ack) ||
 	    nla_put_u32(vendor_event,