platform/x86/intel/sdsi: Set message size during writes

New mailbox commands will support sending multi packet writes and updated
firmware now requires that the message size be written for all commands
along with the packet size. Since the driver doesn't perform writes larger
than the packet size, set the message size to the same value.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lore.kernel.org/r/20240411025856.2782476-2-david.e.box@linux.intel.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/intel/sdsi.c

@@ -252,6 +252,7 @@ static int sdsi_mbox_cmd_write(struct sdsi_priv *priv, struct sdsi_mbox_info *in
 		  FIELD_PREP(CTRL_SOM, 1) |
 		  FIELD_PREP(CTRL_RUN_BUSY, 1) |
 		  FIELD_PREP(CTRL_READ_WRITE, 1) |
+		  FIELD_PREP(CTRL_MSG_SIZE, info->size) |
 		  FIELD_PREP(CTRL_PACKET_SIZE, info->size);
 	writeq(control, priv->control_addr);