bl1: fix switch statements to comply with MISRA rules

Ensure (where possible) that switch statements in bl1 comply with MISRA
rules 16.1 - 16.7

Return statements inside switch clauses mean that we do not comply with
rule 16.3.

Change-Id: I8342389ba525dfc68b88e67dbb3690a529abfeb1
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>

bl1/bl1_fwu.c

@@ -87,6 +87,7 @@ register_t bl1_fwu_smc_handler(unsigned int smc_fid,
 	case FWU_SMC_UPDATE_DONE:
 		bl1_fwu_done((void *)x1, NULL);
 		/* We should never return from bl1_fwu_done() */
+		break;
 
 	default:
 		assert(0);
@@ -747,6 +748,7 @@ static int bl1_fwu_image_reset(unsigned int image_id, unsigned int flags)
 	case IMAGE_STATE_EXECUTED:
 	default:
 		assert(0);
+		break;
 	}
 
 	return 0;