clang-tidy: Fix readability-non-const-parameter diagnostic

For example:

```
/usr/bin/clang-tidy -checks=-*, readability-non-const-parameter -export-fixes /tmp/tmpsuucvvf6/tmpe3yk5vmj.yaml -p=build /mnt/host/andrew/src/openbmc/libpldm/src/platform.c
/mnt/host/andrew/src/openbmc/libpldm/build/../src/platform.c:594:14: error: pointer parameter 'effecter_value' can be pointer to const [readability-non-const-parameter,-warnings-as-errors]
    uint8_t *effecter_value, struct pldm_msg *msg, size_t payload_length)
             ^
    const
```

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I7dbcb94b4ab68f24407fcca1a09e8cc3ab0593b8
diff --git a/src/platform.c b/src/platform.c
index 844dc6f..a805416 100644
--- a/src/platform.c
+++ b/src/platform.c
@@ -591,7 +591,7 @@
 
 int encode_set_numeric_effecter_value_req(
     uint8_t instance_id, uint16_t effecter_id, uint8_t effecter_data_size,
-    uint8_t *effecter_value, struct pldm_msg *msg, size_t payload_length)
+    const uint8_t *effecter_value, struct pldm_msg *msg, size_t payload_length)
 {
 	if (msg == NULL || effecter_value == NULL) {
 		return PLDM_ERROR_INVALID_DATA;
@@ -1263,8 +1263,8 @@
 
 int encode_get_numeric_effecter_value_resp(
     uint8_t instance_id, uint8_t completion_code, uint8_t effecter_data_size,
-    uint8_t effecter_oper_state, uint8_t *pending_value, uint8_t *present_value,
-    struct pldm_msg *msg, size_t payload_length)
+    uint8_t effecter_oper_state, const uint8_t *pending_value,
+    const uint8_t *present_value, struct pldm_msg *msg, size_t payload_length)
 {
 	if (msg == NULL || pending_value == NULL || present_value == NULL) {
 		return PLDM_ERROR_INVALID_DATA;
@@ -1661,7 +1661,7 @@
     uint8_t instance_id, uint8_t completion_code, uint8_t sensor_data_size,
     uint8_t sensor_operational_state, uint8_t sensor_event_message_enable,
     uint8_t present_state, uint8_t previous_state, uint8_t event_state,
-    uint8_t *present_reading, struct pldm_msg *msg, size_t payload_length)
+    const uint8_t *present_reading, struct pldm_msg *msg, size_t payload_length)
 {
 	if (msg == NULL || present_reading == NULL) {
 		return PLDM_ERROR_INVALID_DATA;