modem: ubx: Change request buffer to be void

So this API can be used to send frames with a different encoding than
UBX. This enables UBX drivers to send RTCM3 correction frames using UBX
API, without having to switch over modem pipes.

Signed-off-by: Luis Ubieda <luisf@croxel.com>

Author: ubieda

drivers/gnss/gnss_u_blox_f9p.c

@@ -153,7 +153,7 @@ static int ubx_f9p_msg_send(const struct device *dev, const struct ubx_frame *re
 	data->script.inst.retry_count = wait_for_ack ? 2 : 0;
 	data->script.inst.match.filter.class = wait_for_ack ? UBX_CLASS_ID_ACK : 0;
 	data->script.inst.match.filter.id = UBX_MSG_ID_ACK;
-	data->script.inst.request.buf = req;
+	data->script.inst.request.buf = (const void *)req;
 	data->script.inst.request.len = len;
 
 	err = modem_ubx_run_script(&data->ubx.inst, &data->script.inst);

drivers/gnss/gnss_u_blox_m8.c

@@ -153,7 +153,7 @@ static int ubx_m8_msg_send(const struct device *dev, const struct ubx_frame *req
 	data->script.inst.retry_count = wait_for_ack ? 2 : 0;
 	data->script.inst.match.filter.class = wait_for_ack ? UBX_CLASS_ID_ACK : 0;
 	data->script.inst.match.filter.id = UBX_MSG_ID_ACK;
-	data->script.inst.request.buf = req;
+	data->script.inst.request.buf = (const void *)req;
 	data->script.inst.request.len = len;
 
 	err = modem_ubx_run_script(&data->ubx.inst, &data->script.inst);

include/zephyr/modem/ubx.h

@@ -53,7 +53,7 @@ struct modem_ubx_match {
 
 struct modem_ubx_script {
 	struct {
-		const struct ubx_frame *buf;
+		const void *buf;
 		uint16_t len;
 	} request;
 	struct {