libpldmresponder: Implement GetStateSensorReadings

Register the getStateSensorReadings method and get the state sensor PDR
structure according to the SensorId property.

Tested with JSON file:
https://gist.github.com/lxwinspur/6a40abea7330c25e4d49826e890c4be9

pldmtool raw -d 0x80 0x02 0x21 0x01 0x00 0x01 0x00
Request Message:
08 01 80 02 21 01 00 01 00
Response Message:
08 01 00 02 21 00 01 03 00 00 00

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I4faeb1e85f9fd4a2745f592d37be38c28112f5b9
diff --git a/libpldm/platform.h b/libpldm/platform.h
index 7834f59..bd4d557 100644
--- a/libpldm/platform.h
+++ b/libpldm/platform.h
@@ -157,6 +157,9 @@
 /** @brief PLDM Platform M&C completion codes
  */
 enum pldm_platform_completion_codes {
+	PLDM_PLATFORM_INVALID_SENSOR_ID = 0x80,
+	PLDM_PLATFORM_REARM_UNAVAILABLE_IN_PRESENT_STATE = 0x81,
+
 	PLDM_PLATFORM_INVALID_EFFECTER_ID = 0x80,
 	PLDM_PLATFORM_INVALID_STATE_VALUE = 0x81,