media: dvb-frontends: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break and a return statements
instead of just letting the code fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/dvb-frontends/cx24120.c

@@ -363,6 +363,7 @@ static void cx24120_check_cmd(struct cx24120_state *state, u8 id)
 	case CMD_DISEQC_BURST:
 		cx24120_msg_mpeg_output_global_config(state, 0);
 		/* Old driver would do a msleep(100) here */
+		return;
 	default:
 		return;
 	}

drivers/media/dvb-frontends/dib0090.c

@@ -1765,6 +1765,8 @@ static int dib0090_dc_offset_calibration(struct dib0090_state *state, enum front
 		dib0090_write_reg(state, 0x1f, 0x7);
 		*tune_state = CT_TUNER_START;	/* reset done -> real tuning can now begin */
 		state->calibrate &= ~DC_CAL;
+		break;
+
 	default:
 		break;
 	}

drivers/media/dvb-frontends/drxk_hard.c

@@ -3294,6 +3294,7 @@ static int dvbt_sc_command(struct drxk_state *state,
 	case OFDM_SC_RA_RAM_CMD_USER_IO:
 	case OFDM_SC_RA_RAM_CMD_GET_OP_PARAM:
 		status = read16(state, OFDM_SC_RA_RAM_PARAM0__A, &(param0));
+		break;
 		/* All commands yielding 0 results */
 	case OFDM_SC_RA_RAM_CMD_SET_ECHO_TIMING:
 	case OFDM_SC_RA_RAM_CMD_SET_TIMER:

drivers/media/dvb-frontends/m88rs2000.c

@@ -390,6 +390,7 @@ static int m88rs2000_tab_set(struct m88rs2000_state *state,
 		case 0xff:
 			if (tab[i].reg == 0xaa && tab[i].val == 0xff)
 				return 0;
+			break;
 		case 0x00:
 			break;
 		default: