HID: hid-sensor-hub: Extend API for async reads

Add additional flag to read in async mode. In this mode the caller will get
reply via registered callback for capture_sample. Callbacks can be registered
using sensor_hub_register_callback function. The usage id parameter of the
capture_sample can be matched with the usage id of the requested attribute.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
index ae7c2ba..af4f85a 100644
--- a/drivers/rtc/rtc-hid-sensor-time.c
+++ b/drivers/rtc/rtc-hid-sensor-time.c
@@ -213,7 +213,7 @@
 	/* get a report with all values through requesting one value */
 	sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 			HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
-			time_state->info[0].report_id);
+			time_state->info[0].report_id, SENSOR_HUB_SYNC);
 	/* wait for all values (event) */
 	ret = wait_for_completion_killable_timeout(
 			&time_state->comp_last_time, HZ*6);