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 <lkp@intel.com>
Link: https://lore.kernel.org/lkml/60edca25.k00ut905IFBjPyt5%25lkp@intel.com/Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

drivers/dma/ipu/ipu_idmac.c

@@ -618,6 +618,7 @@ static int ipu_enable_channel(struct idmac *idmac, struct idmac_channel *ichan)
 	case IDMAC_SDC_1:
 	case IDMAC_IC_7:
 		ipu_channel_set_priority(ipu, channel, true);
+		break;
 	default:
 		break;
 	}
@@ -978,6 +979,7 @@ static int ipu_init_channel(struct idmac *idmac, struct idmac_channel *ichan)
 	case IDMAC_SDC_0:
 	case IDMAC_SDC_1:
 		n_desc = 4;
+		break;
 	default:
 		break;
 	}