dmaengine: ipu: Fix fall-through warning for Clang

Fix the following fallthrough warnings (arm64-randconfig):

drivers/dma/ipu/ipu_idmac.c:621:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
rivers/dma/ipu/ipu_idmac.c:981:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Reported-by: kernel test robot <[e-mail]>
Link: https://lore.kernel.org/lkml/[e-mail]/
Signed-off-by: Gustavo A. R. Silva <[e-mail]>

drivers/dma/ipu/ipu_idmac.c

···
 	case IDMAC_SDC_1:
 	case IDMAC_IC_7:
 		ipu_channel_set_priority(ipu, channel, true);
+		break;
 	default:
 		break;
 	}
···
 	case IDMAC_SDC_0:
 	case IDMAC_SDC_1:
 		n_desc = 4;
+		break;
 	default:
 		break;
 	}