MIPS: fix some more fall through errors in arch/mips

Fix these errors:

 arch/mips/cavium-octeon/executive/cvmx-pko.c:489:7: error: this statement may fall through [-Werror=implicit-fallthrough=]
 arch/mips/bcm63xx/dev-flash.c:89:3: error: this statement may fall through [-Werror=implicit-fallthrough=]
 arch/mips/ath79/setup.c:155:17: error: this statement may fall through [-Werror=implicit-fallthrough=]
 arch/mips/ar7/setup.c:50:3: error: this statement may fall through [-Werror=implicit-fallthrough=]

Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Crispin <john@phrozen.org>
Cc: Matthias Schiffer <mschiffer@universe-factory.net>
Cc: "Petr Štetiar" <ynezz@true.cz>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Burton <paul.burton@mips.com>

arch/mips/ar7/setup.c

@@ -69,6 +69,7 @@ const char *get_system_type(void)
 		case TITAN_CHIP_1060:
 			return "TI AR7 (TNETV1060)";
 		}
+		/* fall through */
 	default:
 		return "TI AR7 (unknown)";
 	}

arch/mips/ath79/setup.c

@@ -156,7 +156,7 @@ static void __init ath79_detect_sys_type(void)
 	case REV_ID_MAJOR_QCA9533_V2:
 		ver = 2;
 		ath79_soc_rev = 2;
-		/* drop through */
+		/* fall through */
 
 	case REV_ID_MAJOR_QCA9533:
 		ath79_soc = ATH79_SOC_QCA9533;

arch/mips/bcm63xx/dev-flash.c

@@ -94,6 +94,7 @@ static int __init bcm63xx_detect_flash_type(void)
 		case STRAPBUS_6368_BOOT_SEL_PARALLEL:
 			return BCM63XX_FLASH_TYPE_PARALLEL;
 		}
+		/* fall through */
 	default:
 		return -EINVAL;
 	}

arch/mips/cavium-octeon/executive/cvmx-pko.c

@@ -485,11 +485,11 @@ cvmx_pko_status_t cvmx_pko_config_port(uint64_t port, uint64_t base_queue,
 			config.s.qos_mask = 0xff;
 			break;
 		case CVMX_PKO_QUEUE_STATIC_PRIORITY:
-			/* Pass 1 will fall through to the error case */
 			if (!cvmx_octeon_is_pass1()) {
 				config.s.qos_mask = 0xff;
 				break;
 			}
+			/* fall through - to the error case, when Pass 1 */
 		default:
 			cvmx_dprintf("ERROR: cvmx_pko_config_port: Invalid "
 				     "priority %llu\n",